n e quest volume 1 issue 4 january 2008

Newsletter of North East India Research Forum

N. E. Quest; Volume 1, Issue 4, January 2008, 1



Newsletter of

NORTH EAST INDIA RESEARCH FORUM

http://tech.groups.yahoo.com/group/northeast_india_research/ www.neindiaresearch.org



EDITORIAL It is my proud privilege to be the editor for

the fourth issue of NE Quest. I am really honored and at the outset, I could not but extend my heartfelt gratitude to all the respected and beloved members of the beautiful forum, NE India Research Forum for giving me this opportunity. Interestingly, most of the members of the forum have never met and will probably never meet. Still the bond among us is a reason to smile and it is becoming stronger and stronger day by day. The increase in the number of forum members is very encouraging. I believe, our forum will become one of the focus platforms to cover up entire researchers of NE region.

We heralded in the New Year feeling all ecstatic and as the revelry over we are all back on our feet, surely on a fresh and a positive note. From the experiences and happenings of the past, many thoughts have been knocking in the mind. Among those, in this editorial, I would like to shade light only on two points: one is ‘global warming’ and the other is ‘the faculty crisis in our colleges’.

In many forms, the 19th century concepts have become obsolete with changes in perception and attitude towards various issues ranging from business to entertainment. Surprisingly, the environment exists as an antithesis of its own nature. Though we think ourselves as a part of globalization, in many senses, we are not globalized at all. Now, global warming is emerging as the most severe warning for the mankind. We have to keep aside the geographical barriers to fight against it. We must keep in mind that there is no distinction like Indian carbon or American carbon. Recently, UN report says that there is a small window of opportunity in this century for limiting the global temperature increase to 2 °C. If it is not done, humanity will face a series of climate changes that will wreak havoc on the planet including flooding of coastal areas, crop failures, epidermis, water scarcity, increased natural disaster and many more. Unfortunately, to handle the problem, the gap between scientific evidences and political response remain still large. Developed countries should cut their carbon emissions at least by 80% by the year 2050 with 20-30% cut by 2030 to save the earth

from a complete environmental catastrophe. It is noteworthy that the climate change will affect the world’s poor most, particularly from Africa, Asia and South America. At the recent UN conference on climate change in Bali, global warming was the main issue. Lots of decisions have been taken and we have to look forward for their implementation. Being among the top carbon emitters, India’s stand in this context has to be scrutinized in coming days. Here we need a change in our attitude and have to think more globally. We should be inspired by Al Gore and Rajendra Pachouri, Nobel Peace Prize winners for 2007. Let’s make one resolution in this New Year to save our mother earth from global warming.

Faculty crisis in Indian academic institutions has been a long term problem. The scenario in the colleges of Assam is even more painful and the situation in other NE states is not an exception. It is not only confined to the quantity but also to the quality. Considering the Government’s stand, it seems, the situation will become more dangerous on quality perspective in coming days. The future of the educational standard depends on the budding students and to produce good students we need good teachers. Now the question is, who will join in a college? The answer is ‘no one’ if any other option prevails. The reason? Obviously, the payment scheme. One has to work for two years for a fixed payment that is one third of the fellowship of a research scholar! Isn’t it a strange? We must confess that after a certain age, we have to take some extra responsibilities and for that we need a good earning. To be honest, with knowledge, money is the prime necessity for living. Government has to eye on it for betterment of our future generation. Otherwise, it is difficult to attract the creamy layer students for those jobs. The posts can be fulfilled anyway, as there is no scarcity of pass out students. Still the question of quality remains unanswered. It is for sure, we are going to be the victim and MNCs are ready to take that creamy layer with handful packages.

At last but not the least, I wish all the members a very happy and prosperous New Year and a fruitful ‘Bhogali Bihu’.

Pranjal Saikia



CONTENTS

1. THE FORUM 05 2. NORTH EAST INDIANS MADE US PROUD 06

3. NEWS

a. Research and Developments 07

b. Forum Members in News (awards, fellowships, visit etc) 10 4. INSTRUMENT OF THE ISSUE

Single Crystal X-Ray Diffractometer Mr. Bipul Sarma [ [email protected] ] 11

5. ARTICLES:

a. Nanomedicine: Nanoparticles in Drug Delivery Dr. Jadab Sharma [ [email protected] ] 14

b. Disposable Plastics

Mr. Binoy Kumar Saikia [ [email protected] ] 17 c. Biosensor and its Applications

Mr. Manashjit Gogoi [ [email protected] ] 19 d. Mushroom Poisoning-The Fact Mr. Mahananda Chutia [ [email protected] ] 20 e. Nanocomposites and Their Applications Dr. Sasanka Deka [ [email protected] ] 23 f. Polyurethane Chemistry: Fundamentals and Applications Dr. Smriti Rekha Deka [ [email protected] ] 25

6. Ph.D. THESIS ABSTRACT

a. Newer Catalytic Methodologies for C-N, C-S Bonds Formation and Oxidation of Sulfides, Bromide and Alcohols with H2O2 Dr. Sahid Hussain [ [email protected] ] 27 b. Effect of Solvent Media in Altering the Rates of Diels-Alder Reactions and Other C-C Bond Forming Reactions Dr. Diganta Sarma [ [email protected] ] 34

7. FIRST FIVE IN CHEMISTRY 38 8. INTRODUCTION OF FORUM MEMBERS 39 9. THROUGH THE LENSES OF FORUM MEMBERS, MESSAGE 40 10. HIGHER STUDY ABROAD 42



The Forum North East India Research Forum was

created on 13th November 2004.

1. How we are growing. At the beginning, it was a march hardly with few members and today the forum comprised of a force of more than 175 researchers.

2. Discussions held in the forum • Necessity of directory of all the

members of the forum. • Possibility of organising conference in

the N E India. • Taking initiation on setting up of

South East Asian Scientific Institute. • On selection of Best paper award.

3. Poll conducted and results North East India is lacking behind the rest of the country due to-

1. Geographical constrain =0% 2. Bad leadership = 40% 3. Lack of work culture = 36% 4. Corruption = 18% 5. Apathy from Central Govt. = 4%

Which area of science is going to dominate by creating a great impact on society in next decade?

1. Nanoscience & nanotechnology = 22%

2. Biotechnology = 11% 3. Nanobiotechnology = 38% 4. Chemical Engineering = 0% 5. Medicine = 11% 6. Others = 16% 7. None = 0%

Kindly let us know your view regarding the following topic. What activities of this group you like most ?

1. Research articles= 33% 2. Information about

vacancy/positions available=10% 3. Way to have a contact with all

members =29% 4. Scientific discussions = 14% 5. Others = 2%

Selection of name for Newsletter There were total 36 proposals submitted by members of the forum for the Newsletter. The name proposed by Mr. Abhishek

Choudhury, N. E. QUEST received the maximum number of votes and hence it is accepted as the name of the Newsletter.

How often should we publish our newsletter '' N. E. Quest'' ?

1. Every 3 months = 61% 2. Every 6 months = 38% 3. Once a year = 0%

4. NE-Quest Issues 1. Vol 1 Iss 1 April, 2007 Editor: Dr. Arindam Adhikari 2. Vol 1 Iss 2 July 2007 Editor: Dr. Tankeswar Nath 3. Vol 1 Iss 3 Nov 2007 Editor: Dr. Ashim Jyoti Thakur 4. Current Issue Editor: Mr. Pranjal Saikia

5. Future activities

Proper planning and consequent implementation always play an important role in every aspect. Some of the topics/activities/suggestions which were being discussed, time to time in the forum will get top priorities in our future activities. Those are mentioned here,

• Preparing complete online database of N.E. researchers with details.

• Organising conference in the N.E. region-proposed by Dr. Utpal Bora.

• Research collaboration among forum members.

• Motivate student to opt for science education.

• Help master’s students in doing projects in different organisation-proposed by Mr. Khirud Gogoi.

• Supporting schools in rural areas by different ways.

• Best paper awards.

To run the forum smoothly, to make it more organised and to speed up activities, formation of a committee/team is essential. The combined discussion of the moderators and senior members make the forum feel the importance of Advisors, co-ordinator, volunteer, webmasters etc. Of course it needs more discussion and will be approved by poll.



NE Indians Made Us Proud

Dr. Pabitra Datta

Dr. Pabitra Datta was born in Jorhat, Assam. He received a B.S. degree in Physics and Chemistry from Gauhati University, Assam, India in June 1960; a M.S. degree in Physical Chemistry from Drexel University, Philadelphia, PA in 1962, and a Ph.D. degree in Physical Chemistry from Case-Western Reserve University in 1965. He spent two years of post doctoral work at New York State University at Stony Brook, NY. He joined Addressograph Multigraph Corporation as senior chemist and was promoted to staff scientist within two years. He joined RCA Laboratories as a Member of the Technical Staff in 1974.

His research interests were surface chemistry, photochemistry, plasma deposition, and physical properties of plastics. He received three RCA Laboratories' Outstanding Achievement Awards and an RCA Corporation David Sarnoff Award for Outstanding Technical Achievement. His discovery of the efficacy of a special carbon as a conductive filler led to a practical demonstration of the viability of the conductive disc concept. This breakthrough provided the direction for developing a manufacturable disc technology which is employed in the present product. Dr. Pabitra Datta, at the age of 55 passed away on December 13, 1997 in New Jersey, USA.

Dr. Ruhikanta A. Meetei

Dr. Ruhikanta A. Meetei, at present is working as Assistant Professor at the

prestigious Cincinnati Children's Hospital Medical Centre. He did his B.Sc. (1989) and M.Sc.(1992) from Manipur University, India. Then he did his Ph.D. from Indian Institute of Science, Bangalore, India, in the year 2000. He received several awards which includes, Appreciation Award at the 2003 FARF Scientific Symposium for the discovery of the FANCL gene (2003); Discovery Award at the 2005 FARF Scientific Symposium for the cloning of the FANCB and FANCM genes (2005); American Society of Hematology Junior Faculty Scholar Award (2006-08).

His research focuses on functional analysis of Fanconi anemia gene products. The major research focus includes identification of new FA genes and signal transduction pathways that regulate DNA damage induced activation of the FA-core complex. Important technologies include biochemical purification of multiprotein complexes from human cell extracts, immunoprecipitation, RNAi, and biochemical assays. His long-term research goal is to use Fanconi anemia as a model system to study some of the important fundamental questions of cancer biology in general.

Dr. Khwairakpam Gajananda

In yet another pride for the people of Manipur, one young scientist from Manipur has participated in the 26th Indian Scientific Expedition to Antarctica to explore one of the east Antarctic coastal areas known as Larsemann Hills.

Dr. Khwarirakpam Gajananda who is presently a Scientist (Environment) at the prestigious Shriram Institute for Industrial Research, Delhi University, Delhi was among the 34 members from different Organisations and Universities in India for the expedition to the harshest



continent of the world, Antartica. He was also member of the 18th Indian Scientific Expedition to Antarctica, 16th Winter Over Team (WOT), December 1998 to March 2000.

He did his B.Sc.(1994) in Botany from Manipur University; M.Sc. (1996) in Environmental Sciences, M-Tech (1998) Environmental Science and Engineering, from GJU, Hisar, India. He did his Ph.D in 2003, thesis entitled ‘Study of atmospheric parameters in relation to Antarctic ecosystem over the Schirmacher region of east Antarctica’. In recognition of his achievement in the field of science and technology, he was recognized by the Marquis Who’s Who 2007 in the field of Engineering and Science and Who’s Who in Asia. He was nominated from the Shriram Institute for Industrial Research, Delhi and sponsored by the (NCAOR), Vasco-da-Gama, Goa.

Special Introduction

Mr. Anirban Adhikari

The cover pages of the N. E. Quest have been designed by Mr Anirban Adhikari. Basically from Tinsukia, Assam, he did his graduation from Fergusson College, Pune in Geology. Then he did his masters in Mass Communication. At present, he is working as a Sr. multimedia Developer in a company based in Pune. [The entire members of the forum take the opportunity to acknowledge Mr. Adhikari for his constant support and co-operation.]

……….Editor ---------------------0----------------------

“We are what we repeatedly do.”

Aristotle ---------------------0----------------------

NEWS: Research and Developments ■ University of Minnesota Center for Drug Design and Minneapolis VA Medical Center researchers have discovered a new fast-acting antidote to cyanide poisoning. The antidote has potential to save lives of those who are exposed to the chemical – namely firefighters, industrial workers, and victims of terrorist attacks.Current cyanide antidotes work slowly and are ineffective when administered after a certain point, said Steven Patterson, Ph.D., principal investigator and associate director of the University of the Minnesota Center for Drug Design. “It’s much, much faster than current antidotes,” Patterson said. “The antidote is also effective over a wider time window. Giving emergency responders more time is important because it’s not likely that someone will be exposed to cyanide near a paramedic.” The antidote was tested on animals and has been exceptionally effective. Researchers hope to begin human clinical trials during the next three years. The antidote is also unique because it can be taken orally (current antidotes must be given intravenously) and may be administered up to an hour prior to cyanide exposure. ■ A study which has found an answer to one of the most intractable squabbles in family life -- argumentative and disruptive children are born, not made. A team of international researchers has carried out a study and found a strong genetic influence on whether a child becomes a bully or a victim of bullying, The Guardian reported. In fact, according to the researchers, genetic influences explain 73 per cent of kids' risk of being a victim and 61 per cent of their chance of being a bully. "It's in line with a large body of research which shows that psychological traits have quite a high degree of genetic influence," lead researcher Harriet Ball said. According to Ball of the Institute of Psychiatry at King's College in London, the findings do not imply that genetics



should be used to blame a child for being involved in bullying. "The information should help schools and parents find new ways to deal with bullying." (Courtesy: Times of India) ■ South Korean scientists have cloned cats that glow red under ultraviolet light, as part of research aimed at developing treatments for human genetic diseases, say officials.

A team of scientists led by Professor Kong Il-keun, a cloning expert at Gyeongsang National University in Jinju, produced three glowing Turkish Angoras cats, say the country's Ministry of Science and Technology. According to the Korea Times, the scientists added red fluorescence protein (RFP) genes to the skin cells of the mother cat. They then inserted the skin cells into ova to produce cloned cats genetically modified to contain the RFP gene. "It marked the first time in the world that cats with RFP genes have been cloned," says the ministry of science and technology. "The ability to produce cloned cats with the manipulated genes is significant as it could be used for developing treatments for genetic diseases and for reproducing model [cloned] animals suffering from the same diseases as humans." The technology will also help to develop stem cell treatments - noting that cats have some 250 kinds of genetic diseases that also affect humans. The technology will also help clone endangered animals like tigers, leopards and wildcats, Kong says. (Courtesy: The Ministry of Science and Technology/AFP)

■ British scientists claim to have discovered the mechanism cancer cells use to spread around the body - a breakthrough which could stop the disease right in its tracks. In their research, the

scientists have found that a protein called Ecadherin is essential to keeping cells stuck together and when its levels fall, other proteins move to the surface of the cells and they manage to break away and spread, the Daily Mail reported on Thursday. "Understanding how cancer cells spread is tremendously important for cancer research. It is the ability of tumours to invade other tissues and spread around the body that makes them so dangerous. The cancer just overwhelms the body," lead researcher Chris Ward was quoted as saying. "Potentially, our findings can be applied to the most common form of cancer, carcinoma, found in the breast, lung and gut for example, which makes up 80 to 90 per cent of all cancers," Ward added. The researchers, who used embryonic stem cells to unlock the secret behind how cancer spreads around the body, now plan to create drugs that interfere with this process. "These findings may enhance our ability to come up with more effective drugs". Norman Barrett of the Association for International Cancer Research, which funded the study, said, "Dr Ward and his team are pursuing research which could change the lives of tens of thousands of people in the United Kingdom and many more across the world". (Courtesy: Nature)

■ The Department of Science and Technology (DST) is looking at ensuring enrolment of at least 250 PhD students in nanosciences over the next five years. They will be registered in leading central and state universities and specialized research institutes. While it is not clear how many will graduate in a year, 50 pass-outs a year are needed to ensure India has at least 250 nano scholars by 2012. However, fresh scholars cannot register as it would take them a minimum of three years, if not four, to complete their PhD. But as nanoscience is an inter-disciplinary subject, students already enrolled in courses relating to or contributing to nanosciences could be considered nano research scholars. What exactly the research will focus on will have to be decided by the institution concerned after consulting senior academics and policy-



makers in DST. While this move may ensure that India has a fair number of nano-scholars in five years, scientists are, in fact, looking at a much higher number - 500. The fear is that India will fall desperately short of nano-scholars in five years, by which time the US, Japan and China would have a high number of scholars as well as nano-products. The doubling would mean 100 PhDs per year and this requires a high rate of enrolment. The question is whether this will happen at a time when there is a declining interest in science in general. There’s hope because DST has planned 14 nano-centres in the country, some of which will be labs, and other institutes. If prospects of employment after graduation are good, enrolment is expected to go up rapidly. The allotment of Rs 1,000 crore for nanosciences made by the ministry of science and technology includes a high number of scholarships for students as well as for the new labs and centres. (Courtesy:Times of India) ■ A 20-year-old boy of Golaghat, Arnab Kakati, has been selected by the National Aeronautics and Space Administration (NASA) as its Junior Scientist. Arnab, the only son of Manik Kakati, a junior engineer of ASEB and Sikha Kakati of Old Amolapatty, Golaghat, is studying Engineering at Gandhi Institute of Engineering and Technology of Orissa. Arnab was interested in space science since Class VIII and sent his research paper on Big Bang theory to the World Junior NASA Competition and was later selected as a Junior Scientist of the space agency, which invited Arnab to join and study at NASA. It is pertinent to mention here that no person has ever joined NASA before 32 years of age. So Arnab being just 20 years old, is all set to create a world record. Initially, Arnab’s parents were not interested in sending Arnab to the US but Dr Kalam insisted that he must go there. The Junior Scientist will leave for Delhi on January 15 after signing some documents at Raj Bhavan. He will fly to New York on January 20. (Courtesy: Assam Tribune)

Two Poems Dr. Tankeswar Nath (1) Happy New Year'2008

New year'2008 is in your door step Following your remarkable foot-step

With a bagful magic sticks To apply all the latest techniques

To bring you a bright change In all audible, visible and assessable range

You would be the leader of the leaders To help ride poorest of the poor,

Weakest of the weak To the top of the ladder

To unfold the flag of peace and prosperity Heralding the world Happy New Year.

(2)

New Yew Wish’ 2006

May you have this NEW YEAR, 2006 As an ocean of inspiration, fresh spirit,

confidence and resolve, To drive yourselves and to helps others to

do so Keeping all the problems in the

perspective, Aligning all the goals with the God's good-

will Moving all the loving ways in millions of

relationship, Accepting everything you have as the gift

of God That might be come wrapped in the foil of

hardship, As you know better that, even God in His

human form Couldn't escape the sufferings of body

and mind On the eventual journey, that is

preordained and predestined. (Dr. Tankeswar Nath is an active member of the forum and presently working as a Scientist at Jubilant Organosys, Noida, India.) ---------------------0----------------------



Forum Members in News

Dr. Pranjal Gogoi has joined the group of Prof. Antonio Mourino, Department of Organic Chemistry, University of Santiago de Compostela, Spain as a post doctoral fellow from 15th September 2007. He completed his Ph.D. under the guidance of Dr. Dilip Konwar, Senior Scientist, NEIST, Jorhat in the year 2007.

Dr. Pranjal Baruah has

joined as a post doctoral associate at Department of Chemistry, North Carolina State University with Prof. Daniel L. Comins. He completed his Ph.D. from National Chemical Laboratory (NCL), Pune.

Dr. Smriti Rekha Deka

joined National Nanotechnology Laboratory of CNR-INFM-ISUFI, University of Lecce , Italy for her post doctoral research in the month of January, 2008. Currently she is working on functionalization of nanoparticles with polymers.

Dr. Mukut Gohain

will be joining shortly the group of Prof. Roberto Sanz of University of Burgos, Spain as a post doctoral fellow. He did his Ph.D. under the guidance of Dr. J.S. Sandhu, former Director of NEIST (RRL), Jorhat in the year 2005. He is presently working as a research scientist in Orchid Chemical and Pharmaceutical Ltd., Chennai.

Mr. Khirud Gogoi is

going to join as a Research Specialist at the Howard Houghes Medical Institute, Prof. Steven F. Dowdy Laboratory School

of Medicine, Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, United States. He has recently completed his Ph.D. work under the guidance of Dr. A. Vayjanyanti Kumar, NCL, Pune.

Mr. Lakshindra Chetia will be joining the group of Prof. Prabhat Arya of Ontario Institute for Cancer Research, Canada as a post doctoral fellow from the month of Feb. 2008. He has recently completed his Ph.D. under the guidance of Dr. J. S. Yadav, Director, IICT, Hyderabad.

Mr. Saitanya Kumar

Bharadwaj visited California to present his research paper on “Oxidative Extraction of Bromide from Seawater” in the “PAN IIT Global Conference 2007” held at Santa Clara (Silicon Valley), California, USA from 6-8 July 2007. He is currently doing his doctoral research at Indian Institute of Technology, Guwahati under Prof. Mihir Kanti Chaudhuri, Vice Chancellor, Tezpur University.

Mr. Pankaj Bharali

visited Ruhr University of Bochum (RUB), Germany under a bilateral collaborative project funded jointly by DST, India and DAAD, Germany during October to December 2007. He is currently pursuing his doctoral research at Indian Institute of Chemical Technology (IICT), Hyderabad under Dr. B. M. Reddy.

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“Honest differences are often a healthy sign of progress.”

Mahatma Gandhi ---------------------0----------------------



Instrument of the Issue: Single Crystal X-ray Diffractometer

Mr. Bipul Sarma

Fundamentals:

It is known to all that in 1895, Wilhelm Roentgen, Professor of Physics from Worzburg, Bavaria who discover the possibility of using electromagnetic radiation what we now know as the X-ray. Single-crystal X-ray diffraction or X-ray crystallography is an analytical technique in which X-ray methods are employed to determine the complete three dimensional molecular structures including the absolute stereochemistry of chemical substances. Max von Laue, in 1912, discovered that crystalline substances act as three-dimensional diffraction gratings for X-ray wavelengths similar to the spacing of planes in a crystal lattice. The precise knowledge of the molecular geometry is becoming increasingly important in nearly all fields of chemical and biological research.

The basic building block in a crystal (arrangement of molecules in a precisely regular way repeated in all directions) is the unit cell. A crystal is made up of millions of identical unit cells arranged in a three-dimensional crystal lattice. Each crystalline substance has a unique set of lattice constants (a, b, c, α, β, γ) which define the size and shape of the unit cell (Figure 1).

Fig. 1

Based upon the lattice constants and symmetry the system may be classified as triclinic, monoclinic, orthorhombic, tetragonal, cubic, trigonal or hexagonal. Finally, each substance may be further classified as belonging to one of 230 three dimensional space groups.

When a beam of parallel monochromatic x-rays strikes a single crystal, the crystal acts as a three-dimensional diffraction grating and produces an x-ray diffraction pattern (Figure 2). This diffraction consists of a three dimensional array of reflections that satisfy the conditions of Bragg’s law. Bragg’s law:

n λ= 2d sin θ

where n is a small integer giving the order of diffraction, λ is the wavelength of the incident x-rays, d is the distance between a set of parallel lattice planes, and θ is the angle between the incident x-ray beam and the atomic lattice plane in the crystal

Fig. 2

The spatial arrangement of the reflections in an x-ray diffraction pattern bears a reciprocal relationship to the dimensions of the unit cell in the crystal. Each reflection may be assigned a set of indices (hkl) which indicate its location in the diffraction pattern or reciprocal space. The diffraction pattern in reciprocal space has a Fourier transform relationship to the electron density in the unit cell in real space. Experimentally, the unit-cell parameters for a crystalline specimen may be determined from an analysis of the spatial arrangement of the reflections in its x-ray diffraction pattern. The X-ray diffraction pattern consists of the superposition of scattered waves of varying amplitude and phase. Each



diffraction maximum or reflection has associated with it a structure factor F(hkl) measured relative to the scattering by a single electron. The structure factor may be represented as a complex vector: F(hkl) = A(hkl) + iB(hkl) where A(hkl) and B(hkl) are the real and imaginary components of F(hkl).

Instrumentation:

The basic components of typical single-crystal X-ray diffractometer include: 1. An X-ray source consisting of a high voltage X-ray generator. 2. Copper or Molybdenum target X-ray tube. 3. Associated shutter shield tube. 4. Attenuators and safety interlocks. 5. Monochromator or X-ray mirror system. 6. An incident-beam collimator. 7. Three or four circle goniometer system that allows the specimen to be precisely oriented in any position while remaining in the X-ray beam. 8. Video camera or microscope for aligning the specimen and indexing crystal faces. 9. CCD (Charge-Coupled Device)-based two-dimensional X-ray detector system. 10. Low-temperature attachment for cooling the specimen during data collection. 11. Microprocessor-based interface module that receives commands from a host computer and carries out all real-time instrument control functions to drive goniometer motors, monitor the detector system, open and close the shutter and monitor collision sensors and safety interlocks. 12. Host computer with a large hard disk mass storage device. 13. Video monitor and keyboard, and diffractometer control programs to control the data collection strategy and to send commands to the microprocessor. Steps taken in the experiments: 1. Selection and mounting of a suitable crystal. Ideal size of a single crystal must

be 0.1 mm to 0.5 mm, not cracked and not twinned. 2. Stable crystals of typical organic, organometallic or coordination complexes can usually be grown by slow recrystallization from common solvents. Other types of compounds may require the use of sublimation, zone refinement, solvent diffusion, low temperature and inert-atmosphere techniques.

Goniometer Head

3 Cycle goniometer

Charge Coupled Device (CCD)

Bruker-AXS CCD diffractometer



Suitable single crystal is glued or securely attached to a goniometer head (sample holder) in an arbitrary orientation. The goniometer head is then placed on the base of the goniometer and the crystal is optically aligned in the center of the incident X-ray beam using a video camera or microscope. The orthogonal X, Y, and Z translations on the goniometer head are adjusted until the crystal is centered. A preliminary rotational image is then collected for one minute with the CCD detector to screen the crystal (also known as rotaframe) for analysis and to select suitable parameter values for subsequent steps. In order to determine the unit cell, a preliminary set of frames is measured. For example, three sets of frames are collected in different parts of reciprocal space. These frames are then processed to locate spots on individual frames and to then determine the centers of reflections. An auto-indexing routine selects the appropriate reduced primitive unit cell and calculates the corresponding orientation matrix and lattice constants. This preliminary unit cell is then refined using a non-linear least-squares algorithm and converted automatically to the appropriate crystal system and Bravais lattice. This new cell is refined by the non-linear least-squares algorithm to yield an accurate orientation matrix which may be used to index crystal faces and to carry out integration calculations after intensity data collection. When electrons have sufficient energy to dislodge inner shell electrons of the target material, characteristic X-ray spectra are produced. Molybdenum is the most common target material for single-crystal diffraction, with MoKα radiation = 0.7107Å. These X-rays are collimated and directed onto the sample. When the geometry of the incident X-rays impinging the sample satisfies the Bragg Equation, constructive interference occurs. A detector records and processes this X-ray signal and converts the signal to a count rate which is then output to a device such as a printer or computer monitor. In final stage, data reduction and refinement using specific software (SAINT, SHELXTL etc) we can visualize the molecule in 3D.

Reference: 1. Clegg, W. 1998, Crystal Structure

Determination, Oxford University Press, Oxford

2. Glusker, J. P., Trueblood, K. N. 1985, Crystal Structure Analysis, A Primer; Oxford University Press, New York.

3. BRUKER AXS INC. 5465 East Cheryl Parkway Madison, WI 53711-5373, USA; BRUKER AXS GmbH, D-76181 Karlshuhe, Germany.

4. Stout G. H., Jensen, L. H. 1989, X-Ray Structure Determination; A Practical Guide; John Wiley & Sons, New York.

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”An investment in knowledge always pays the best interest” Benjamin Franklin

---------------------0---------------------- “The important thing is not to stop questioning. Curiosity has its own reason for existing. One

cannot help but be in awe when he contemplates the mysteries of eternity, of life, of the marvelous structure of reality. It is enough if one tries merely to comprehend a little of this mystery every day. Never lose a holy curiosity.”

Albert Einstein ---------------------0----------------------

“Education: that which reveals to the wise, and conceals from the stupid, the vast limits of their

knowledge.” Mark Twain



Articles: Nanomedicine: Nanoparticles in Drug Delivery Dr. Jadab Sharma

The field ‘Nanomedicine’ is emerging as a major area of research recently, the process of diagnosing, treating, and preventing disease and traumatic injury, relieving pain, and preserving and improving human health, using molecular tools and molecular knowledge of the human body. Traditional treatment lacks precision, i.e., inadequacies in the ability to administer therapeutic moieties so that they will selectively reach the desired targets with marginal or no collateral damage has largely accounted for the discrepancy.

The major component for the

controlled drug delivery is ‘Nanovector’- for the administration of targeted therapeutic and imaging moieties, for which the precise patterning of surfaces of nanoparticles is the most essential part. These nanovectors are mainly developed for the use in cancer treatment and are intravascularly injectable. Their envisioned use is for the in vivo, non-invasive visualization of molecular markers of early stages of disease; the argeted delivery of therapeutic agents, with a concurrent, substantial reduction of deleterious side effects; and by a combination of first two- the interception and containment of lesions before they reach the lethal or even the malignant phenotype, with minimal or no concurrent loss of quality of life. There are two ways to achieve this goal: polymer therapeutics and nanoparticles based therapeutics or a combination of both. Polymer therapeutics includes rationally designed macromolecular drugs, polymer-drug, and polymer-protein conjugates, polymer micelles. Similarly, several types of nanoparticles for the controlled drug delivery have been attempted, for example, gadolinium-based, iron oxide based nanoparticles and multiple-mode imaging contrast nano-agents that combine magnetic resonance with biological targeting and optical detection have been

used clinically and in research protocols. Interestingly, combining the surface chemistry and self-assembly processes leads to the development of gold nanoparticles based nanovectors, which offers several advantages in respect to its multiple application possibilities. In essence, the requirements/strategies for polymer based drug delivery systems are essentially the same with nanoparticles based delivery systems, while both the systems have several advantages and disadvantages one over another. However, the most significant aspect of drug delivery systems is to combine vast knowledge of nanomaterials, biochemistry, supramolecular chemistry, polymer chemistry, and the appropriate development of superior mathematical models. The scheme 1 shows the major requirements and strategy adopted for developing nanomaterials based controlled drug delivery systems.

Scheme 1.

We wish to employ our knowledge on

nanomaterials advantageously to develop different nanovectors by a combination of supramolecular techniques, nanomaterial science, bio-chemistry, polymer science, and self-assembly methods. Accordingly, following two major areas will be discussed briefly: 1. Nanomaterials: Nanovectors in general have at least a tripartite constitution: (a) a core constituent material, (b) a therapeutic and/or imaging payload, (c) biological surface modifiers, which enhance the bio-distribution and tumor targeting of the nanoparticles dispersion.

NANOPARTICLES (SYNTHESIS)

FUNCTIONALIZATION

LOADING

MAKE THEM TARGET SPECIFIC

BIO COMPATIBILITY

CELL PERMEABILITY

IMAGING (FLOURESCEIN PROBE)

DRUG MOLECULES

NANOVECTOR

INTRODUCTION INTO THE BODY FLUID

DETECTION OF TARGET

CONTROLLED RELEASE OF DRUGS

TRACING THE TRAJECTORY & IMAGING

OF TARGET



Therefore, a comprehensive

investigation should be carried out focusing three main areas: (a) finding appropriate nanoparticles as core, (b) suitable therapeutic materials for curing and early diagnostic, and (c) biocompatible surface layers or coating materials. Several types of nanoparticles have been developed and many more are still to come. A judicious choice of synthesis protocol will help to find suitable nanomaterials as core, for example spherical gold nanoparticles of various sizes, gold nanoplates, gold nanocages, alloy nanoparticles, and core shell nanoparticles. Nanoparticles have the advantage of stability and tenability over conventional staining methods. Attaching gold nanoparticles to specific oligonucleotides that, when added to a sample of DNA, would bind to complementary gene sequences. The gold nanoparticles can also be attached to proteins, opening up the possibility of controlling more complex biological processes such as protein folding and enzymatic activity. Magnetic nanoparticles have been used as MRI contrast enhancer, e.g. gadolinium-based nanoparticles, iron-oxide-based nanoparticles, and many other magnetic nanoparticles. Interestingly, Dextran-coated, ultra small paramagnetic iron-oxide nanoparticles were shown to outperform conventional gadolinium MRI contrast in terms of intra-operative permanence of imaging enhancement, inflammatory targeting, and detectability at low magnet strength in the surgical treatment of brain tumors. In essence, this area of research is comparatively difficult in terms of functionalization of surfaces

and needs active and innovative research efforts. Another class of targeting methods uses external energy as a trigger for the localized activation of cytotoxic action and has been demonstrated in animal models. Examples are the use of focused ultrasound to burst lipid encapsulated microbubles, photodynamic therapy on silica based carriers, and the localized thermal ablation of cancer lesions using gold nanoplates and nanocages by optical activation in the near-infrared region. Another emerging class of nanovectors is made of silicon and silica nanoparticles. Porosified silicon is biodegradable, with kinetics that is much more rapid than those of biodegradable polymers, and therefore, releases drugs with previously unattainable time profile.

Currently, there are limited methods

available for longitudinal and non-invasive in vivo assessment of the transport kinetics of carrier-based therapeutics, such as those relying on liposomes. Increased interest in nanocrystal quantum dot (QD) technology as fluorescent probes possessing unprecedented brightness, photostability, and multi-color capability has made apparent their promising potential for live tracking of single cell and in vivo processes. Presently, QD biorecognition is largely achieved through attachment of antibodies to the QD surface, resulting in a bio–inorganic complex combining biomolecular-specificity with fluorescence. A less explored approach is to use small ligands or synthetic analogs that when conjugated to the QD, would bind not only to receptor proteins, but also serve to activate signaling cascades that regulate cellular phenotype and behavior. Surface modification and composition of complexed QD nanostructures have been confirmed and bioactivity of ligands and ligand-QD complexes have also been tested using functional imaging based assays. Development of this QD-based capability bears significance for development of tools for studying inter-molecular interactions, assessing effectiveness of drug compounds, and visualization of cellular function for a variety of biological studies.

Drug A PEG Drug B Contrast enhancer Targeting moieties Permeation enhancer



2. Therapeutic (imaging) payload and biological surface modifiers: Drug eluting stents, cage-like metal devices coated with a drug/polymer mixture, significantly advance the treatment of cardiovascular disease. The molecular targeting of nanovectors containing active agents might be attained by the conjugation of active recognition moieties to the surface of a nanovector. Specificity is then increased at the expense of added complexity in the nanoparticles preparation. The use of molecularly targeted nanovectors has several potential advantages over conventional antibody-guided therapy: the delivery of much greater therapeutic payloads per target recognition event; the ability to carry multiple, potentially different targeting agents, providing selectivity enhancement; the ability to integrate means to bypass biological barriers; and co-localized delivery of multiple agents, resulting in targeted combination therapy. The metal cage keeps weakened blood vessel walls open and the polymer coating elutes a drug which prevents scar tissue formation, which can re-block the vessel. Formulation of drug eluting coatings remains a challenge since the coating must be thin and conformal, the polymer matrix must be tailored to incorporate high concentrations of drug and to control the elution of the drug, and the coating must withstand the severe deformations of the metal cage upon insertion into the vessel. Polymer blend coatings often offer advantages not found in single polymer coatings: ability to tune drug elution rates and mechanical properties by varying the ratio of the two polymers.

The characterization of structural properties of novel dicationic (gemini) surfactant-based DNA complexes as micro/nano-scale self-assembling delivery systems for cutaneous gene therapy has been described and discussed as related to measured transfection efficiencies. In order to characterize and control the adhesive behaviors of nanometer scaled stimuli-responsible gel particles designed for oral peptide delivery, their interaction with artificial mucin layer in the small intestinal solutions has to be determined.

The gel particles have to be designed to exhibit behaviors responsive to temperature and pH in solutions, consequently protecting the incorporated peptide drug under harsh acidic conditions in the stomach, adhere and penetrate to the mucin layer in the small intestine, and thereafter release the drugs.

Photodynamic therapy (PDT) is a novel photochemical process for producing localized tissue necrosis, which involves the activation of a photosensitizing drug in the target tissue with light of a specific wavelength matched to an absorption peak of the photosensitizer in the presence of molecular oxygen. However, the photosensitivity is still a major side effect of PDT in clinical treatment. Micelles as photosensitizer carriers are able to provide many advantages, including improvement of drug solubility, reduction in photosensitivity, long circulation time and tumor targeting. An investigation towards new class of carriers will be helpful to solve this problem (e.g. shell cross-linked (SCK) nanoparticle based on poly(ε-caprolactone)-poly(ethylene glycol)-aldehyde have been demonstrated to successful delivery of protoporphyrin IX). A viable strategy to non-invasively track the carrier in vivo is to employ the same carrier loaded with contrast-enhancing agents such as iodine and gadolinium. If these agents are retained within the carrier, they may act as surrogates for therapeutic molecules and allow for non-invasive tracking of the carrier in vivo using computed tomography (CT) and magnetic resonance (MR) imaging devices.

Cationic nanoparticles have been formulated from a polycationic Polyhydroxylamine (PT) with low pKa and polyanionic PolyAcrylic Acid (PA) that form binary polyelectrolyte complexes (PECs). It has been observed

NN

NSH

O

O

O

O

O

H

H

H

Peptide with permanent dipole moment (Variable chain length and charge)

(L1)



that particles spontaneously form on component mixing with sizes between 80-700nm and particle charge 3-30mV. Plasmid containing GFP (Green fluorescing protein, pGFP) can be incorporated (by pre-binding pGFP to PT) and assessed. Nanoparticle polymer systems below 1 micron in size have potential roles as carrier systems. An advantage of using polyhydroxlamine based PECs is that they should allow release of bound DNA as a polyanion from a PEC at relatively mild pH conditions, due to the low pKa (below 9) of the polycationic Polyhydroxylamine.

Such nanoparticles have potential use as cationic transfection agents that can release under benign physiological conditions compared to similar particles formulated with ‘hard’ polyamines with higher pKa (>pH9). Simple addition of polyhydroxylamine and poly-acrylic acid (w/w), under mildly acidic conditions, causes spontaneous formation of cationic nanoparticulate PEC dispersions with a range of size and charge. Several other examples include nanoconjugates of β-poly(L-malic acid) (PMLA), Lysolipid temperature sensitive liposomes (LTSLs) etc. We had synthesized ligand and fluorescein probe for their application as imaging material and surface modifier (shown above as L1 and L2). About the author: Jadab Sharma was born in India in 1974. He obtained the B.S. (1997), the Master (2000), and then the Ph.D. (2006) degrees

in Chemistry, under the supervision of Prof. K. Vijayamohanan, at the National Chemical Laboratory, Pune, India. After a short Postdoctoral Fellowship at the University of Padova under Prof. Flavio Maran, he has joined the reaseach group of Prof. T. Imae, Keio University, Japan and is continuing his research at National Taiwan University of Science and Technology, Taiwan under her supervision. His areas of research interest are electrochemistry, functionalized nanomaterials, organic synthesis (small ligands for nanoparticles, such as peptides), and solar cell. Disposable Plastics

Mr. Binoy Kumar Saikia

The use of certain chemicals such as plasticizers and chlorofluorocarbons in the manufacture of plastics produces ecological and environmental problems. The tremendous amount of plastic items used today creates waste disposal problems. Plastic waste in the sea poses direct danger to fishes. Small fishes have been found dead with their digestive tracts clogged by fragments of plastic foam they had ingested. Plastic bags have suffocated sea animals to death. The disposal of plastic waste by landfilling and incineration has both caused certain problems. As plastics are chemically tailored for long life, they do not generally undergo decomposition in the landfill site. Thus the plastic waste can last for a long period in the environment. Incineration of plastic waste produces air pollutants such as hydrogen chloride from polyvinyl chloride and other chlorine containing polymers. The hydrogen chloride produced can cause acid rain, which damages the environment.

SH

O OHOH

NH

O

14CH2 CH2

O

O

Ligand with fluorescein properties

(L2)



Development of degradable plastics and recycling of plastics as possible solutions to pollution problems as the use of plastics can hardly be divorced from modern living, the associated pollution problems have to be solved. To tackle the problem of waste disposal, degradable plastics are being developed and processes for recycling of plastic waste are now underway.

Degradable plastics:

Plastics normally undergo extremely slow degradation because the enzymes in microorganisms tend to attack only at the ends of the polymer chains. Attempts have been made to develop plastics, which are more degradable. There are several types of degradable plastics: (1) Biopolymers – polymers made by living organisms. Poly (hydroxybutyrate), PHB, is natural polyester made by certain bacteria. Microorganisms found in soil and natural water sources are able to break down the polymer. The degradation of this polymer in the environment is usually completed within 9 months. However, PHB is 15 times more expensive than poly (ethene). (2) Photodegradable plastics – light-sensitive functional groups such as carbonyl group (C=O) can be incorporated into the polymer chains. The long polymer chains will be broken down under the action of sunlight into shorter fragments, which can then be biodegraded. (3) Synthetic biodegradable plastics– made by incorporating starch or cellulose into the polymer during production. As microorganisms digest the starch or cellulose, the plastic is broken down into tiny pieces. The very small pieces left over have a large surface area, which greatly speeds up their biodegradation.

Degradable plastics have been used for making six-pack beverage rings, trash bags and disposable diapers.

Recycling of plastics:

Since plastics are essentially derived from petroleum, which has limited

reserve, disposal of plastics by way of land filling or incineration is a waste of useful resources. Such wastage may be reduced by recycling, in one form or another, as outlined below:

(1) Direct recycling – this applies only to thermoplastics. The plastics in the waste are separated, cleaned, pulverized, and remoulded into plastic items. The success of this method depends on the collection of clean and uncontaminated plastic waste, which is the most difficult step. In 1988, the Society of the Plastics Industry (SPI) developed a uniform coding system that makes it possible to sort waste plastics. The SPI (Society of the Plastic Industry) coding symbols are shown next. Code numbers 1 to 6 refer to specific polymers, while 7 number refers to all other types. Once the waste plastics are separated, they can be reprocessed into new plastic items. The regenerated plastics usually have deteriorated properties due to repeated thermal and mechanical processing, and can only be used for articles, which are not subject to high stress. Recent development on recycled plastics focuses on converting the plastic products with short service lives, such as foam, wrap and containers, to products with longer service lives, such as construction materials and plastic pipes.



About the author: Binoy Kumar Saikia passed M.Sc. in Inorganic Chemistry from Cotton College (Gauhati University) in 2000. He then joined in North East Institute of Sciences & Technology, Jorhat, as a Project Assistant and completed his research work on X-ray diffraction and spectroscopic investigation of Assam coal. Presently he is engaged as a Technical staff in the Department of Chemical Sciences, Tezpur University, Tezpur, India. His areas of research interest include X-ray diffraction, FT-IR spectroscopy, coal chemistry, acid mine drainage, water & soil pollution.

Biosensor and its applications

Mr. Manashjit Gogoi Introduction:

Biological systems are the most efficient systems as they reached the present state after hundreds of thousands of years of continuous evolution. In order to increase our efficiency, we learn from biological systems and mimic them. People are trying to employ the ways, living being exchange messages and communicate with the surrounding i.e. how they sense signals from the surrounding and how they process the signals. Biosensor is a result of biomimicry of biological sensing system. Biosensors are analytical devices that combine a biological recognition element with a physical or chemical transducer to selectively and quantitatively detect the presence of specific compound(s) in a given environment. These biosensors are accurate, reliable and simple to operate, can be easily fabricated with minimal sample preparation. Biosensors have many advantages such as simple, low cost instrumentation, highly selective and fast response time. Biosensor:

Biosensor is defined as a self contained integrated device that is capable of providing quantitative or semi-

quantitative analytical information using a biological recognition element which is connected with the transducer element (IUPAC, 1969). The biological recognition element may be an enzyme, antibody or a binding protein and a transducer to convert the biochemical reactions into quantifiable electronic signals that can be processed, transmitted and measured. A biosensor has two components i.e. a receptor and a detector. The receptor is responsible for selectivity of the sensor

(Fig1).

Type of biosensors:

Biosensors can be classified based on biological parts and the basis of their transducers.

Based on biological components:

a) Catalytic (Enzyme) based

b) Tissue/cell biosensor based

c) Affinity biosensor based

Based on the transducers:

a) Eectrochemical biosensors

b) Piezoelectric crystal

c) Optical biosensor

d) Calorimetric

Application of biosensors:

Clinical: Biosensors can play a vital role in disease diagnosis. Implantable biosensors can provide real time measurements in critical condition and supply data of important pathological parameters. Research is going on for the development of lab-on-chip device where biosensor will provide complete data for a given analysis.

Amplifier

-Enzymes -Cells, Microorganisms Tissues and organelles -Antibodies and Receptors -Nucleic Acids

Electrodes Transistors Thermistors

Optical detectors Piezoelectric

crystal

Biosensor

Bioreceptors Physical Transducer

Sample

MicroelectronicsData Processing

0.12345



Agriculture: In this field, biosensors can be used to monitor the degree of ripening of fruits, presence of pesticides and herbicides in food products and sugar analysis from sugarcane in sugar industry etc.

Bioprocess industry: In this area, biosensors can play a vital role in online monitoring of substrate and product analysis in microbial fermentation and downstream processing of biological samples.

Environmental: In environmental sector, biosensors can be used for monitoring of organophosphate pollutants, Heavy metals and toxic radicals in the environment and determination of Biological Oxygen Demand in industrial effluents.

Food industry: Biosensors are being used for monitoring of sugar concentration in soft drinks and confectionery syrups and pulps and detection of food adulterants and food toxins.

Defence: Biosensors can be used in defence application to detect the presence of detection of explosives like RDX and TNT and Chemical and Biological warfare agents.

Conclusion:

Biosensor is a multidisciplinary area; it needs the expertise knowledge of life sciences, chemistry, material science, electronics, software, MEMS and VLSI technologies. With the progress of these areas, compact, cheap, robust, high sensitive, accurate biosensors are hitting the market everyday. The research and development and commercial exploitation of biosensor is not fully explored yet. Presently, biosensor market is growing at a rate of 6.3% per annum, the market volume will be $8.2 billion by 2009[1]. So, there is huge potential in this field to explore. In India, the biosensor research is in infancy stage. If we do not start to work on biosensor now, we will be great loser in near future in terms of jobs, money and market. So, it is right time to explore the opportunities in the field of biosensor.

About the author: Manashjit Gogoi hails from Jorhat, Assam. He did B.E. in Chemical Engineering from Assam Engineering College in 2001 and completed M. Tech. from Tezpur University in Bioelectronics in 2006. In between this period, he worked in NEIST, Jorhat as a project Assistant and CFTRI, Mysore as a GATE-JRF. Presently he is in IIT, Bombay pursuing his Ph.D. on the topic "Temperature sensitive nanostructured magnetic materials and nanovesicles for combined cancer hyperthermia and drug delivery".

Mushroom Poisoning – The Fact

Mr. Mahananda Chutia

Mushrooms are not a taxonomic group. They are the macrofungus with a distinctive hypogeous or epigeous fruiting body, large enough to be seen with the naked eye and to be picked by hand (Chang & Miles, 1992). The number of mushroom species on the earth is estimated to be 140 000, suggesting that only 10% are known (Lindequist et al, 2005). Assuming that the proportion of useful mushrooms among the undiscovered and unexamined mushrooms will be only 5%, which implies 7000 yet undiscovered species will be of possible benefit to mankind (Hawksworth, 2001). Mushrooms can be used for successful bio-prospecting for the benefits of mankind as both the macro and macroscopic fungus have the potential for



the production of commercially important bioactive secondary metabolites. Again, some of the mushrooms are deadly poisonous too. Naturally, majority of the wild mushrooms are known as poisonous; for which many people affect on mushroom poisoning due to the consumption of wild mushroom.

The habit of eating wild mushrooms is

very common in India especially in the rural areas. Many people are admitted to hospitals due to mushroom poisoning every year and many lose their lives because of the complications (Erguven et al, 2007). Mushroom poisoning is common especially among people from low socioeconomic level who consume mushroom in daily nutrition. Why some wild mushrooms are poisonous?

Poisonous mushrooms contain at least two different types of toxins, each of which can cause death if taken in large enough quantities. All the mushroom poisoning (called as mycetism) is due to its chemical constituents in that particular species. These chemical goups are alpha-amanitin (deadly), bolesatine (in Boletus satanas), coprine (poisonous with alcohol), orellanine (deadly), gyromitrin (deadly), muscarine (sometimes deadly), arabitol (cause gastrointestinal irritation). One group of poisons, known as amatoxins, blocks the production of DNA, the basis of cell reproduction. This leads to the death of many cells, especially in the liver, intestines and kidney. Other mushroom poisons affect the proteins needed for muscle contraction and therefore reduce the ability of certain muscle groups to perform. The type of poisoning of different group of toxins is also different. How to identify poisonous mushroom?

Identifying of poisonous mushrooms is very difficult, costly and time-consuming. Identification is done basically on the characteristic features of the color, gills, spores, stalks and base portion of the mushroom. The habitat of the mushroom

is also an important feature for identification. There are no such traditional common tests or rules that can accurately determine the safety or toxicity of a poisonous mushroom. However, there are some common guidelines to know about the poisonous group of mushroom although it is not the scientific or correct one which could prove to be a deadly mistake.

Anyway, a mushroom is considered

poisonous if:

The mushroom stains when bruised The mushroom turns garlic blue or

black when cooked together The mushroom has scales, warts or

other types of rough surfaces The mushroom secretes a milky sap The mushroom turns a silver coin

black when rubbed against it The mushroom tarnishes a silver

spoon when cooked with it A mushroom is considered safe if: • If it is cultivated • The mushroom grows on wood • Slugs or other insects eat the

mushroom • Squirrels, rabbits, or other wildlife eat

the mushroom • The mushroom does not have a ring or

skirt on the stalk • The mushroom is dried, boiled, salted

or pickled in vinegar • The mushroom is pure white in color

What are the symptoms of mushroom poisoning?

The type of symptoms of mushroom poisoning is also different species to species due to their different groups of toxins present (Unluoglu and Tayfur 2003). The symptoms are –

Toxin groups CYCLOPEPTIDES

Symptoms begin with sharp abdominal pains, violent vomiting and persistent diarrhea. In 3-4 days, the patient begins to worsen with symptoms of kidney and liver failure and may die.



Toxin groups ORELLANINE Symptoms are nausea, lack of

appetite, headache, severe burning thirst and kidney failure.

Toxin groups IBOTENIC ACID-MUSCIMOL

Common symptoms are confusion, muscle spasms, delirium and continuous visual disturbances. Vomiting usually does not occur. Patient can recover after treatment.

Toxin groups ONOMETHYLHYDRAZINE

The patient experiences a feeling of fullness in the stomach, vomiting and watery diarrhea, headache, fatigue, cramps. Pain in the liver and stomach followed by jaundice.

Toxin groups MUSCARINE-HISTAMINE

Symptoms are sweating, drooling, diarrhea, watery eyes, blurred vision, pinpoint pupils, decreased heart rate and blood pressure.

Toxin groups COPRINE

Symptoms occur if taken with alcohol. Flushing of the face and neck, a metallic taste in the mouth and an increased heart rate.

Toxin groups PSILOCYBIN-PSILOCYN

Symptoms are in thinking which alter consciousness. Hallucinogenic begins after 30-60 minutes of ingestion. It may cause anxiousness or uncontrolled laughter.

Toxin groups ARABITOL

Sudden severe vomiting and mild to severe diarrhea with abdominal cramps are the symptoms. Diagnosis and treatment

There is no specific antidote for mushroom poisoning. However, the death rate of the mushroom poisoning may be decreased. Early replacement of lost body fluids has been a major factor in improving survival rates. Therapy is aimed at decreasing the amount of toxin in the body. Initially, attempts are made to remove toxins from the upper

gastrointestinal tract by inducing vomiting or by stomach pumping.

Early removal of mushroom poison by way of an artificial kidney machine (dialysis) has become part of the treatment program now a day. This is combined with the correction of any imbalances of salts (electrolytes) dissolved in the blood, such as sodium or potassium. An enzyme called thioctic acid and corticosteroids also appear to be beneficial, as well as high doses of penicillin (Benjamin, 1995). In Europe, a chemical taken from the milk thistle plant, Silybum marianum, is also part of treatment. When liver failure develops, liver transplantation may be the only treatment option. The mortality rate has decreased with improved and rapid treatment. However, according to some medical reports death still occurs in 20-30% of cases with a higher mortality rate of 50% in children less than 10 years old. Conclusion

It is also important to remember that most mushroom poisons are not destroyed or deactivated by cooking, canning, freezing, drying or other means of food preparation. So, the important factor to prevent mushroom poisoning is to avoid eating wild or noncultivated mushrooms. Early diagnosis and treatment in mushroom poisoning can be life saving. Alpha amanitin levels should be checked as soon as possible, if amanita poisoning is suspected. If laboratory tests to detect the toxin cannot be performed the time of occurrence of symptoms, the features of the ingested mushroom, the clinical picture and the family anamnesis can give defined important clues about the type of intoxication (Erguven et al, 2007). Moreover, providing public education on mushroom poisoning is very much important in prevention of intoxication as well as encouraging early admission to hospitals.

Reference: 1. Chang ST, Miles PG (1992)

Mushrooms biology—a new discipline. Mycologist. 6: 64–65.



2. Hawksworth DL (2001) Mushrooms: the extent of the unexplored potential. Int. J Med Mushrooms, 3:333–7.

3. Lindequist U, Niedermeyer THJ, Julich WD (2005) the Pharmacological Potential of Mushrooms. eCAM. 2(3):285–299

4. Benjamin DR (1995) Amatoxin syndrome. In: Mushrooms: poisons and panaceas — a handbook for naturalists, mycologists and physicians. New York: WH Freeman and Company. pp 198–214

5. Erguven M, Yilmaz O, Deveci M, Aksu N, Dursun F, Pelit M, Cebeci N (2007) Mushroom poisoning. Indian J. of Pediatric, 74 (9): 847-852

6. Unluoglu I, Tayfur M (2003) Mushroom poisoning: an analysis of the data between 1996-2000. Eur J Emeg Med, 10: 23-26.

About the author: Mahananda Chutia did his M.Sc. (2003) in Botany with specialization in Microbiology from Gauhati University, Assam. After qualifying NE SLET, he joined as a project assistant at NEIST, Jorhat, Assam in the Plant Science Division. His research interests include Microbial diversity and Molecular Biology, Cell Biology and Immunology. Nanocomposites and Their Applications

Dr. Sasanka Deka

A composite is one or more distinctive components dispersed in a continuous matrix creating a compositional heterogeneity of the final solid structure. A typical conventional composite is glass-fibre-reinforced plastic (GFRP) that is widely used in aircrafts, large containers and automotive parts. Some other

examples are; SiC in high strength ceramic materials, ZrO2 in superplastic ceramics, magnetic metallic phases of Fe and Co in magnetic materials, etc. Composite materials are used in large number of multifunctional applications, from cryogenic to corrosion resistance, from biomedical to engineering, from automotive to thermoplastics, from high density recording to GMR, etc [1,2]. A ‘nanocomposite’ is defined as a composite in which the distinctive component(s) is/are in the nanometer range. The accepted length scale for the nanophase is less than 100 nm in at least one dimension. The continuous materials can be ceramic, metallic, organic or polymers, either in the bulk form or as a thin film. Nanocomposites are a special class of materials originating from suitable combinations of two or more nanoparticle samples or nanosized objects in some suitable medium, resulting in materials having unique physical properties and wide application potential in diverse areas. Novel properties for the nanocomposites can be derived from the successful combination of the characteristics of parent constituents into a single material. Moreover, these materials typically consist of an inorganic (host) solid containing an organic component or vice versa. Or they can consist of two or more inorganic/organic phases in some combinational form with the constraint that at least one of the phase of various features be in nanosize [3].

Composites are expected to exhibit

superior properties or better performance than their elemental or monolithic counterpart. Most of the property changes can be estimated by some rule of mixtures. The simplest change of a composite property, Pc, is monotonic increases or decrease with the increase of volume fraction, Vi, of the added components; which is represented by the following equation



where Pi is the added component property and n is an experimental parameter ( �1 ≤ n ≤ 1). Nanocomposites differ from their bulk components in terms of the strong interactions of grains around the grain boundaries. There are six properties of interest in nanocomposites. These are: mechanical, magnetic, electrical, optical, quantum dots and catalytic properties. Nanocomposites exhibit unique behavior due to three effects (i) the smaller size effect, (ii) the large grain boundary effect, and (iii) the quantum confinement effect. Moreover, they exhibit high reactiveness during synthesis and in processing situations. Thus, these conditions leads to increase in strength and hardness of ceramic matrix nanocomposites, lowering in melting point and increase in electrical resistivity of metallic matrix nanocomposites, increase in absorption of UV wavelength in polymer matrix nanocomposites, increase in shielding the electrostatic field for semiconducting matrix nanocomposites, etc. Nanocomposites find their applications in various areas, such as electromagnetic wave absorber, biocompatible magnetic nanofibre, conducting polymer nanocomposites, cheaper optoelectronic, photonic and electronic devices, integrated circuit (IC) products, etc [4].

Out of the application oriented nanocomposites, magnetic nanocomposites in which magnetic species are dispersed within nonmagnetic or magnetic matrices are practically very useful. Magnetic recording, GMR, magnetic refrigeration, etc., are some important areas in which magnetic nanocomposites have importance [3,5].

One newly studied nanocomposite material is the polymer/metal/ferrite composite. The importance of such a system is that after little modification, these can be used as capacitors and inductors. Moreover, they have advantages over the current ferromagnetic-ferroelectric ceramic composites in various terms. The main advantages of magneto-polymer composites are the ability to tailor materials for special purposes, low cost of production, availability to develop totally new material

morphologies and device geometries, etc [6]. Polymer based magnetic nanocomposites with high initial permeability and high dielectric constant are interesting because of their flexibility, compatibility and easy fabrication nature. Polymer/metal/ferrite composites consist of a polymer, a magnetic metal and a ferrite material either on the coronal surface or in the interior core of the polymer microdomains as filler. This is a totally innovative composite material, where properties of both the matrix polymer and the nanocomposite components are synergized. In such polymer/metal/ferrite composites, high initial permeability can be obtained by dispersing ferrite particles with large initial permeability in the polymer matrix as filler, and in addition, dielectric constant can be enhanced over their polymer matrix. Thus, merging these two different properties in polymer based composites, it will be easier to overcome the disadvantages of purely ceramic based composites. Finally we can expect some more enhanced applications from the nanocomposites. References: 1. J. B. Schutz, Cryogenics 38 (1998) 3. 2. D. Xie, I.-D. Chung, G. Wang and J.

Mays, J. Biomater. Appl. 20 (2006) 221.

3. P. M. Ajayan, L. S. Schadler and P. V. Braun, Nanocomposite Science and Technology, (Wiley-VCH GmbH & Co. KGaA, Weinheim, 2003).

4. H.-L. Tasi, J. L. Schindler, C. R. Kannewurf and M. G. Kanatzidis, Chem. Mater. 9 (1997) 875.

5. H. Zeng, J. Li, J. P. Liu, Z. L. Wang and S. Sun, Nature 420 (2002) 395.

6. D. Y. Godovsky, Adv. Poly. Sci. 153 (2000) 163.

About the author: Sasanka Deka hails from Kamrup, Assam. He has completed his B.Sc. degree from B. Barooah College, Guwahati in 1998 and Master degree from the department of Chemistry, Gauhati University in 2000. After clearing CSIR-UGC-NET he joined



in the National Chemical Laboratory and obtained Ph.D. degree in 2007. His primary interest of research areas are materials science, nanomaterials, oxide nanoparticles, magnetism and semiconductor. He has 11 publications in peer-reviewed international journals with few more in the national journals, symposia and conference proceedings. Currently he is a postdoctoral fellow in National Nanotechnology laboratory, Lecce, Italy. The present supervisor of his work is Dr. Liberto Manna. Polyurethane Chemistry: Fundamentals and Applications

Dr. Smriti Rekha Deka

Polyurethanes constitute a very important class of industrial polymer. It is available in different forms such as elastomers, toughened polymers, blends and foams. The different classes of polyurethanes are characterized by the presence of urethane linkage as common feature. The initial discovery of polyurethane was made by Otto Bayer and his co-workers of I.G. Farbenindustrie at Leverkusen, Germany in 1937.1

Segmented polyurethanes are block

copolymers of (AB)n type consisting of alternating rigid and flexible segments. They exhibit properties characteristic of cross linked elastomers over a wide temperature range and can be processed by techniques used for plastics and fibres. They are a unique class of thermoplastic material. Due to the different polarity and chemical nature of the rigid and flexible segments, they tend to separate into two phases referred to as soft and hard phases. The structure of a segmented polyurethane molecule and domain

formation are schematically drawn in Figure 1 and Figure 2 respectively.

Figure 1. The structure of a segmented polyurethane molecule.

The soft segment is either polyester, polyether or polyalkyl glycol with a molecular weight between 600-3000. The hard segment is normally an aromatic diisocyanate that has been chain extended with a low molecular weight diol. The polymerization reaction is catalyzed by tertiary amines, such as dimethylcyclohexylamine, and organometallic compounds, such as dibutyltin dilaurate or bismuth octanoate. Furthermore, catalysts can be chosen based on whether they favor the urethane (gel) reaction, such as 1,4-diazabicyclo[2.2.2]octane (also called DABCO or TEDA), or the urea (blow) reaction, such as bis-(2-dimethylaminoethyl)ether, or specifically drive the isocyanate trimerization reaction, such as potassium octoate. The most important and widely used synthetic route for the preparation of polyurethane is the addition polymerization between a diisocyanate and a diol. As the polymerization proceeds through a step-wise mechanism, it is often named as step-growth polymerization.

Figure 2. The two phase structure of bulk-polymer (polyurethane)

Hard Segment

Soft Segment



Polyurethanes with flexible polyol backbone have generally good retention of properties at low temperature which make them suitable candidates for use in adhesives, coatings etc. Toughened polyurethanes are engineering polymers. They also have biomedical applications. Modification of polymers to improve their performance as well as to widen their field of application has been a fascinating field of research. The scope of utility of polyurethanes can be further widened by block copolymerization with vinylic monomers.

Block copolymerization in general

could be achieved through anionic, cationic and radical polymerization. The synthesis of block copolymers through free-radical polymerization technique has always been more attractive than through anionic and cationic polymerization techniques. Free radical polymerization can be initiated either by thermally or photochemicaly. Compared to thermal initiation of free-radical polymerization, light induced initiation has the advantage of being applicable at room temperature. It also provides selective activation of photolabile groups in the monomer, macromonomer etc. A polymer with inchain or pendent photo labile groups is termed as polymeric photoinitiator or macrophotoinitiator. Polymeric initiators having photolabile groups in the main chain could be used to initiate light induced free-radical block copolymerization. The applicability of this method however depends on the availability of synthetic procedures appropriate to incorporate photolabile groups into the main chain of polymers which can then act as photoinitiators. Various organic disulphides act as photoinitiators on being irradiated in the range 254 nm to 366 nm. The disulphides are further found to act as iniferters (initiator, transfer agent and terminator). This concept of iniferters and the model for living radical polymerization were proposed by Otsu et al.2,3 Besides disulphides, benzoin group also acts as photoinitiator. Incorporation of photolabile disulphide group or benzoin into a

polymer backbone makes it a polymeric or macrophotoinitiator. Irradiation of such macrophotoinitiator in presence of vinylic monomers such as methyl methacrylate (MMA), styrene (St), acrylonitrile (AN), 2-hydroxy ethyl methacrylate (HEMA) result in block copolymers.

Polyurethane–vinyl block copolymers

are high-performance polymers which can be used as thermoplastic elastomers. Most applications of block copolymers are stemming from their ability to form microdomains in solution and in bulk. Current applications of block copolymers include thermoplastic elastomers and compatibilization of polymer blends. The potential uses of block copolymers in immerging technologies like nanotechnology, nanolithography, photonics, and controlled drug delivery are enormous. Due to their potential biocompatibility they are widely employed in the manufacture of biomedical devices. Recent studies have also demonstrated that these materials can exhibit fascinating electro-responsive and optical properties. References 1. Hepburn. C., Polyurethanes

Elastomers, Applied Sci., London, 1991.

2. Otsu. T., Yoshida. M., Makromol. Chem. Rapid. Commun., 3, 127, 1982.

3. Otsu. T., Yoshida. M., Tazaki. T., Makromol. Chem. Rapid. Commun., 3(2), 133, 1982.

About the author: Smriti Rekha Deka was born in Jorhat, Assam. She did her B.Sc. from J.B. College, Jorhat and completed her M.Sc and Ph.D. from Gauhati University (Organic Chemistry). Recently she has joined National Nanotechnology Laboratory of CNR-INFM-ISUFI, University of Lecce , Italy for her post doctoral research. Currently she is working on functionalization of nanoparticles with polymers. The title of her thesis is 'Synthesis of Polyurethane Macrophotoinitiator and its application in Block Copolymerization with Vinylic Monomers'.



Ph.D. Thesis Abstract: Newer Catalytic Methodologies for C-N, C-S Bonds Formation and Oxidation of Sulfides, Bromide and Alcohols with H2O2

Dr. Sahid Hussain

Catalysis plays an important part in

rendering chemical transformations very effective, highly selective and environmentally safer. Catalysis is in deed not only one of the principal tenets of ‘Green Chemistry’ but also is an integral part of it. The timely publication of a compendium on ‘Green Chemistry and Catalysis’ by Sheldon1 puts this point affirm beyond any scope of imagination. The invention of a new clean and appropriate catalyst for a chosen transformation is extremely important. And for this, a clear understanding of the chemistry of a prospective catalyst or a catalytic system and the transformation on which the catalyst is to be applied upon is an essential prerequisite. The domain of catalysis thus expands by crossing boundaries of several sub-disciplines including bio and abio chemistry and material science, for instance. The world market of catalysts is ca 12 billion US dollars, and the chemical transformations leading to specific products through catalysis is estimated to be 1.2-6.0 trillion US dollars.2 This in itself underscores the need to develop practical catalytic processes involving homogeneous, heterogeneous and bio-catalysts. In fact catalysis in one form or the other dominates the contemporary chemical literature. In consonance with the current trend and appreciating the need for clean chemistry practices, the present thesis has been framed mainly on the development of newer catalysts. The chosen organic

transformations include aza- and thia-Michael condensations, selective oxidation of organic sulfides to the corresponding sulfoxides and the peroxo form of vanadium bromoperoxidase cofactor mimicking radical bromination of toluenes and electrophillic oxidation of benzylic alcohols to the corresponding aldehydes. The catalysts have been drawn from Cu(acac)2[acac = acetylacetonate, C5H7O2

–

], B(OH)3, Na2B4O7.10H2O, (NH4)2HPO4 and two newly synthesized and fully characterized compounds, [VO2F(dmpz)2] and K[V(O2)3]. Water has been used as solvent as far as practicable and H2O2 has been our oxidant of choice. H2O2 is an innocuous reagent that produces water as the only by product thereby rendering it be an ecobenevolent chemical species.3 It can be highly cost effective if used in a controlled fashion.

The text of the thesis has been

distributedover a total of six chapters. Chapter 1: Introduction and Scope of Work in the Area:

This chapter presents a brief account of prior arts of hetero-Michael reactions and the peroxo-based oxidation chemistry. Importance of C-N, C-S bonds formation and oxidations of sulfides, bromide and alcohols with H2O2 in the field organic synthesis are highlighted. It also emphasizes the need for development of safe and cost effective catalysts and catalytic systems for various industrially important reactions.

Contemporary importance of the

chosen aspects of chemistry selected for the present Ph. D. research provides a large scope of the work and much more beyond.

Chapter 2. Details of Materials and Methods, and Equipment

The sources of chemicals and solvents, methods for quantitative chemical estimations, determination of elements and details of all the equipment used for physico-chemical studies are provided in this chapter. The



characterization was done using appropriate physico-chemical techniques. Chapter 3. Catalytic Hetero-Michael Reactions:

The Michael reaction since its discovery in 1889 has been one of the most frequently studied reactions in organic synthesis for C-C, C-N, C-O and C-S bonds formation. The conjugate addition of a nitrogen or sulfur nucleophile to an electron rich or electron deficient electrophile, known as aza- or thia-Michael reaction to form a C-N or C-S bond, respectively, constitutes a key reaction in biosynthesis as well as organic synthesis. β-Aminocarbonyl and β-thiocarbonyl compounds are the adducts of aza- and thia-Michael reactions, respectively, usually encountered in naturally occurring biologically active compounds such as alkaloids and polyketides and are widely used throughout the chemical industry as a basic intermediate to prepare pharmaceutically or agrochemically useful chemicals. Owing to their wide ranging biological properties, they are much sought after as chemotherapeutic agents for the treatment of various diseases. They serve as essential intermediates in the synthesis of γ-amino alcohols, diamines, β-amino acid derivatives, β-lactam antibiotics, β-acylvinyl cation, homoenolate anion equivalents, β-calcium antagonist diltiazem and natural products. The thia-Michael reaction also provides an elegant strategy for the chemoselective protection of the olefinic double bond of conjugated enones due to ease of generation of the double bond through removal of the sulfur moiety by copper(I) induced oxidative elimination. Some thia-adducts of amides are known to have topical relevance to the investigation of host-guest interactions and are also useful as photographic development accelerators. Consequently, the development of newer and practical synthetic routes to these important compounds has stimulated constant interest of many research groups over the years. Chapter 3 reports a few newer methods for aza-, thia-Michael

reactions and X-ray structure of three β-sulfidocarbonyls. In order to make the presentation expressive, Chaper 3 has been divided into four section.

3.1 Cu(acac)2 Immobilized in Ionic Liquids: A Recoverable and Reusable Catalytic System for Aza-Michael Reactions

Copper(II) acetylacetonate immobilized in ionic liquids has been shown to efficiently catalyze the aza-Michael reaction of amines with α,β-unsaturated carbonyl compounds to produce the corresponding β-amino carbonyl compounds with great alacrity in excellent yields (Scheme 3.1). The reactions are far more facile than those reported earlier. The methodology works very well using a low catalyst loading with easy catalyst and solvent recycling. This method is capable of being scaled up, if desired.

3.2 Boric Acid: A Novel and Safe Metal-Free Catalyst for Aza- and Thia-Michael Reactions

Boric acid efficiently catalyzes the conjugate addition of amines or thiols to α,β-unsaturated compounds to produce β-amino and thia-compounds, with great alacrity and excellent yields, in water under mild conditions (Scheme 3.2). Aromatic amines do not participate effectively in the reaction. The use of boric acid, being a safe chemical, as the catalyst and water as the reaction medium are important attributes in the present protocol. The reaction is capable of being performed neatly in the chosen solvent at ambient temperature without catalyst poisoning. The thia-Michael reactions can be performed in ethanol or methanol, as reported in this section.

NH

R'

R

N

R'

R

R1

R2+ X

R1

R2

X

X = CO2Me, CONH2, CN, COCH3, NO2

Cu(acac)2, [Bmim]BF4

rt, 10-120 min

R1=R2= alkyl, benzyl, aryl, H

R'=alkyl, aryl, HR= alkyl, H;

Scheme 3.1

60-98%



3.3 Borax as an Efficient Metal-Free Catalyst for Hetero-Michael Reactions

Borax, a naturally occurring material, very efficiently catalyzes the conjugate addition of thiols, dithiols and amines to α,β-unsaturated ketones, nitriles, amides, aldehydes and esters in aqueous medium to afford the corresponding Michael adducts in good yields at room temperature (Scheme 3.3). Recycling of the catalyst and scaling up of the reactions are important attributes in this catalysis. The reactions of thiols and dithiols were relatively more facile than the corresponding amines.

An internal comparison of the results of thiol additions with those of amine additions, under similar experimental conditions, shows that the former are more facile than the latter. Indeed, this observation is in agreement with the result of some earlier kinetic studies. Based on kinetic data it was predicted that –SH groups were many times more reactive

than amines in aqueous alkaline solution. A comparison of the present results with those of the corresponding boric acid catalyzed aza-Michael reactions suggests that under similar experimental conditions borax appears to be either as good as or somewhat better than boric acid in catalyzing the chosen reactions.

3.4 X-Ray Studies on β-Sulfidocarbonyls Evidencing Intermolecular Hydrogen Bonded Self-Assembled β-Pleated Sheet Structures

In the course of our research endeavor

in this area, three crystalline compounds were obtained by the conjugate addition of cysteine, 1,2 and 1, 3 dithiols each to acrylamide catalyzed by borax in water at room temperature. The compounds have been characterized well by chemical analyses, IR and NMR spectroscopic studies. The hitherto unprecedented crystal

structures of the chosen compounds not only support their molecular structures but also provide evidence for strong intermolecular hydrogen bonding with β-sheet type of molecular rearrangement in addition to the occurrence of rather unconventional C–H---O and C–H---S type of H-bonding in the crystal lattice.

It is expected that the chosen

compounds might serve as suitable probes to study hydrogen-bonding interactions in

R1

NHR

XR1

NR

XBoric AcidH2O, rt,

R2

R2

R3

R3

R = alkyl, aryl; R1= alkyl, H ; R2 = R3 = alkyl, HX = CO2Me, COMe, CN, CONH2

1-6 h70 95%

10mol%+

Scheme 3.2

X RSXBoric Acid

R2

R2

R3

R3

+RSH10-20 mol%

water, rt , 2-12h79 – 82%

R = alkyl; R1= alkyl, H ; R2 = R3 = alkyl, HX = CO2Me, COMe, CN, CONH2

Crystal packing in adduct 1


R1

R2

EWG

R1

R2

EWG

SR

NHR3

R4

EWG

R4N

R3 EWG

RSH +Borax (10 mol%)

r.t., water5–180 min / 70–97 %

+Borax (10 mol %)

r.t., water

1.5–8 h / 25–92 %

R = alkyl / aryl; R1 = alkyl / aryl / –(CH2)–; EWG = CO2Me, CN,CONH2, COMe, COPh

Scheme 3.3



(c.f. protein structure) and obtain insights into the realm of sulfidoamide chemistry.

Chapter 4. Development of New Catalysts for Selective Oxidation of Sulfides with H2O2

Apart from the transformations highlighted above, oxidation is a widely used multifarious chemical process having application in almost all of the important fine and specialty chemical industries manufacturing pharmaceuticals, agrochemicals etc. A wide variety of reagents, catalysts and catalystic systems were developed and well documented. Endeavour has been made to overcome the problems associated with oxidation such as overoxidation and less selectivity. Some success has been achieved but search is still on to get an ideal process. In the current scenario, the bio-inspired, or metal-free, catalysis seems to be the safest option since the nature allows the bioorganic reactions utilizing enzyme vanadium bromoperoxidase (VBrPO) as the catalyst for bromination and oxidation (c.f. organic sulfides) of the required organic molecules. The knowledge obtained from our studies on peroxo vanadium chemistry and the literature information on VBrPO reactivity encouraged us to develop new and cleaner protocols for oxidations.

In this chapter, we have described the

oxidation of sulfides with a newly synthesized vanadium complex [VO2F(dmpz)2], borax and phosphate as the catalyst and H2O2 as the oxidant. As a logical extension, oxidative desulfurization of diesel was attempted with [VO2F(dmpz)2]–H2O2 and a reasonable success has been achieved. A

brief account of this experiment has been included in this chapter.

4.1 Development of a New Catalyst [VO2F(dmpz)2] for Oxidation of Organic Sulfides

The synthesis VO2F(dmpz)2 has been achieved by conducting the reaction of V2O5 with NH4HF2 and 3,5-dimethyl pyrazole under the specified conditions. It has been ascertained from repeated reactions that pH=4.2 of the reaction is crucial for its successful synthesis. The lemon yellow compound is stable for a long period. The single crystal X-ray analysis shows that the compound is a penta coordinated vanadium (V) mononuclear species.

Coordinative unsaturation of vanadium(V) in [VO2F(dmpz)2] provides an additional site for H2O2 coordination and resemblance of pyrazole with imidazole set some arguments in favor of VBrPO mimic. And with the so designed mimic, we carried out oxidation reactions of sulfides with H2O2.

Various aliphatic and aromatic groups attached to sulfur atom and refractory sulfur (e.g. dibenzothiophene (DBT), 4-methyl-DBT and 4,6-dimethyl DBT) compounds were subjected to oxidation with H2O2 catalyzed by VO2F(dmpz)2. The oxidations were selective affording sulfoxides. In case of allylic sulfides oxidation, sulfoxides were formed without the cleavage of carbon-carbon bond.

As a sequel to our research and in

view of the pressing need for reducing the sulfur content of diesel to an ultra low level, it was thought worthwhile to try out the efficacy of the newly developed catalyst for the purpose. Accordingly, the [VO2F(dmpz)2]–H2O2 system was applied to diesel containing >2200 ppm of sulfur.


V2O5 + NH4HF2

Methanolic soln. of Dmpz

ORTEP view of VO2F(dmpz)2



The fuel containing oxidized organic sulfurs was purified by passing through an adsorption column packed with Al2O3 and activated charcoal (90:10). The output was found to contain 150-700 ppm of sulfur. This process has been scaled up to 2 L. 4.2 Borax and Phosphate Catalyzed Selective Oxidation of Organic Sulfides

The selective oxidation of sulfides to sulfoxides and sulfones has been achieved in high yields at room temperature with borax as a recyclable catalyst and H2O2 as the terminal oxidant by varying pH of the reaction medium (Scheme 4.2). The borax–H2O2 system can chemoselectively oxidize alkyl as well as aryl sulfides in presence of oxidation prone functional groups such as C=C, –CN, –OH. Some refractory sulfides, viz, dibenzothiophene (DBT) and 4-methyl-DBT are also capable of being oxidized quite effectively though with less selectivity. The oxidations of DBTs are especially important in the context of transportation fuel chemistry research targeting desulfurization of diesel and gasoline, for instance.

Selective oxidation of organic sulfides to the corresponding sulfoxides seems to be possible with (NH4)2HPO4, as well. Thus, (NH4)2HPO4–H2O2 oxidized a variety of organic sulfides at pH 7 or 8 (Scheme 4.3). The reaction worked well in the chemoselective oxidation of sulfides in presence of C=C, –CN –OH groups. Unfortunately, the catalytic system could not bring about the oxidation of refractory sulfurs. A comparison of the results of borax catalyzed reaction with those of (NH4)2HPO4, clearly suggests that the former is a better catalyst.

Chapter 5. VBrPO-Mimicking Catalysis in Water for Radical Bromination as well as Electrophillic Oxidation, and Oxidative Extraction of Bromide from Sea Water

Environmentally cleaner access to benzyl bromides that serves as precursors of benzyl alcohols appears to be quite a synthetic challenge, while the global requirement for benzaldehydes that are obtained from the corresponding alcohols is very high (> 20,000 tons per year). Benzyl halides including benzyl bromides are synthesized from the corresponding toluenes. Benzylic bromination of toluenes is accomplished by radical bromination. The bromination of organics with molecular bromine is fraught with the problems of handling transportation and use owing to its high toxicity and corrosive nature. To ease out the problems several methods were developed, but the brominating agents used therein are not ecobenevolent, not easy to handle and are highly toxic. In the given situation, bio-inspired catalysis seems to be the promising option since the nature allows such reactions utilizing vanadium bromoperoxidase (VBrPO) enzyme as the catalyst for bromination of the required organic molecules.

Besides the radical bromination,

oxidation of alcohols to aldehydes or ketones is a fundamental transformation in chemical industries. However, green catalytic oxidation of benzyl alcohols as opposed to the spate of stoichiometric oxidations is a relatively grey area that needs attention because most of the several green procedures have been based on costly metals thereby rendering the process economically non viable, in many instances.

In view of this and also because of the

availability of a highly peroxygenated vanadium(V) species, [V(O2)3]–, at our disposal, it was considered quite apt to use this as a precatalyst for oxidative brominations, and selective oxidation of alcohols with H2O2. While we are engaged in the triperoxovanadate(V) catalyzed

R R'S R R'

S

R R'S

OOO

Borax (10 mol%)H2O2, CH3OH

pH 6 or 7

Borax (10 mol%)H2O2, CH3OH

pH 10 or 11

Scheme 4.2

10-95%45-92% 5–24h 3–24h

R R'S

R R'S

O(NH4)2HPO4 (10 mol%)

H2O2, H2O or CH3OH

Scheme 4.3

pH 7 or 865-89%2–12h



reactions, it was observed that our [VO2F(dmpz)2] catalyst very efficiently catalyzed the oxidation of bromide to tribromide, Br3

–, by H2O2. This encouraged us to try out the oxidative extraction of bromide from sea water using this catalyst. 5.1 An Improved Synthesis of [K(V(O2)3] and its Use as a Precatalyst for Radical Bromination and Oxidation

The synthesis of [K(V(O2)3] has been achieved from the reaction of V2O5 with H2O2 in the presence of relatively large concentration of alkaline medium with the molar ratio of V2O5 : H2O2 : KOH being maintained at 1: 42 : 42.5. The complex was obtained by the addition of ethanol, which fascilated precipitation. The temperature, time and order of addition of the reagents play crucial role in the successful synthesis of the catalyst. A minor change in the reaction conditions leads to the formation of mixed peroxo complexes.

We have investigated benzylic

bromination of toluene and selective oxidation of benzyl alcohols with H2O2 as the terminal oxidant and the optimal reaction conditions have been worked out. Under the optimized reaction conditions, a wide variety of toluene and benzylic alcohols were converted to their corresponding benzyl bromide and benzaldehyde selectively and efficiently in good yields (Scheme 5.1). The catalyst can be recycled five times without the loss of activity. The procedures are scaled up upto 10 g and 5 g for toluene and benzyl alcohol, respectively. The peroxovanadium complex isolated from the aqueous solution at pH 4 or 5 before the reactions as well as after extracting the oxidized product from the reaction mixture was identified as K3[(O2)2OV-(µ-OH)-VO(O2)2].H2O. This is indeed the active catalyst. Based on the present studies and the knowledge gathered from the studies of peroxovanadium chemistry, we proposed the reaction mechanisms. The yield of the targeted product in each case has been good to very good.

Scheme. 5.1

5.2 [VO2F(dmpz)2] Catalyzed Oxidative Extraction of Bromide from Sea Water

The fact that the peroxo form of the enzyme vanadium bromoperoxidase (VBrPO) catalyzes the oxidative bromination of organic molecules in the marine environment, and that VBrPO mimicking catalysts catalyzes the in situ oxidation of Br – to Br3

– by H2O2 in the presence of catalytic amount of acid is highly significant in the realm of peroxovanadium(V) chemistry. By conjuring the bio and abiotic events, it was anticipated that a suitable VBrPO mimicking catalyst might enable extraction of bromide from sea water in a very soft way. Accordingly, several catalysts have been developed in our laboratories and the performance of [VO2F(dmpz)2] as a representative example has been reported in this section (Scheme 5.2a). A slightly concentarted pre-analysed sea water generally known as ‘bittern’ was obtained from a bromine producing industry (Tata Chemicals Ltd., India). The bromide content of the bittern was 2 g/L.

In the present study, [VO2F(dmpz)2]

has been shown to efficiently and selectively catalyze the oxidation of Br – in bittern by H2O2 in the presence of a small amount of acid. The oxidised bromide has been isolated from the water solution using either tetrabutyl ammonium or benzyltriethyl ammonium ion as the corresponding tribromide. The extraction of the Br– has beeen found to be nearly quantitative (85%, Scheme 5.2b).

K[V(O2)3].3H2O / H2O2 / H+

KBr, CTAB, water, 6h

CH3Br

X X

Br

Br

X

+

5-9%72-78%

K[V(O2)3].3H2O / H2O2 / H+

CTAB, water

OH

O

H

X X55-85%

ambient light



The identity of the compound has

been ascertained from the results of IR, UV and X-ray crystallography.

Chapter 6. Microwave Assisted Synthesis of Quinolines

The Friedlaender synthesis of quinolines is a classic method, that involves two steps, wherein reduction of o-nitro aryl aldehyde is first achieved followed by the condensation of enolizable carbonyl compound in presence of a Brønsted acid or a Lewis acid catalyst. The relative instability of the intermediate, o-amino aldehyde, with its strong tendency to undergo self-condensation rendered such reactions rather complicated. Subsequently, the synthesis has undergone several modifications over the years. Considering the development, it was quite imperative that quinolines synthesis required further attention to obviate the need to maintain stringent experimental conditions, use of expensive catalysts, and prepare and isolate the o-amino carbonyls as synthetic precursors.

Reduction

NH2

CHO

Condensation N

O

NO2

CHO

Traditional synthesis

Scheme 6.1

In view of the above, a relatively more versatile yet simplified procedure was perceived based on the reasoning that the substrates like o-nitrobenzaldehyde and enolizable ketones could be made to interact in the presence of SnCl2 under microwave irradiation without using any solvent. Our arguments have been that under microwave irradiation, the reduction of o-nitrobenzaldehyde by SnCl2 to the corresponding amino derivatives, in situ enolization of the chosen ketones, and enhanced dipole-dipole interactions between the activated reaction intermediates would lead to an instantaneous condensation to afford quinolines without the use of any solvent or catalyst. The strategy worked well affording the desired products in respectable yields (Scheme 6.2).

NO2

CHO O

N

SnCl2.2H2O

MW

Scheme 6.2

+

This protocol is applicable to a wide range of enolizable ketones (cycloalkyl, n-alkyl, alkyl aryl). It is evident from the results that alkyl and cycloalkyl enolizable ketones readily cyclized with the in situ generated o-amino benzaldehyde to afford the corresponding quinolines in good to very good yields. Chapter 6 is based on a relatively small piece of work entailing this work.

Conclusion

In conclusion, we have developed some newer catalytic methodologies for the aza- and thia-Michael reactions, and oxidation of sulfides, bromide and alcohols. The catalytic protocols are very easy to operate, safe, cost-effective and efficient. We have also developed bio-mimetic catalysts for radical bromination and electrophillic oxidation of alcohols,

QABr3

QA+

VO2F(dmpz)2, H2O2/ H+

Br– (Sea bittern)

QA+= Tetrabutyl ammonium or Benzyltriethyl ammonium

Scheme 5.2b

85, 87%

QA+

3Br – QABr3VO2F(dmpz)2, H2O2, H+

QA+= Tetrabutylammonium or Benzyl triethyl ammonium

Scheme 5.2a

Br3–

0.01 : 3.2 : 1.2



bromide and sulfides using H2O2 as the oxidant. The use of cost-effective, innocuous, recyclable catalysts and environmentally benign oxidant and eco-friendly solvents are some of the important attributes in the protocols. The work embodied in the thesis satisfies the tenets of “Green Chemistry” and it is anticipated that the results reported herein will provide scope for further studies.

Reference 1. A. Sheldon, I. Arends and U.

Hanefeld, Green Chemistry and Catalysis Wiley-VCH, Weinheim, 1st Ed., 2007.

2. R. Noyori, Proceedings of Indian National Science Academy 2006, 72, 267.

3. R. Noyori, M. Aoki and K. Sato, Chem. Commun. 2003, 1977.

4. M. L. Kantam, V. Neeraja, B. Kavita, B. Neelima, M. K. Chaudhuri and S. Hussain, Adv. Synth. Catal. 2005, 347, 763.

5. (a) M. K. Chaudhuri, S. Hussain, M. L. Kantam and B. Neelima, Tetrahedron Lett. 2005, 46, 8329; (b) M. K. Chaudhuri and S. Hussain, J. Mol.Catal. A: Chemical 2007, 269, 214.

6. S. Hussain, S. K. Bharadwaj, M. K. Chaudhuri and H. Kalita, Eur. J. Org. Chem. 2007 361.

7. S. Hussain, G. Das and Mihir K. Chaudhuri, J. Mol. Structure 2007, 837, 190-196

8. M. K. Chaudhuri, S. K. Dehury, S. Hussain, A. Duarah, N. Gogoi and M. L. Kantam, Adv. Synth. Catal. 2005, 347, 1349.

9. M. K. Chaudhuri, S. K. Dehury, Sahid Hussain, A. Duarah and N. Gogoi, Org. Prep. Proc. Int. 2006, 38, 331.

10. M. K. Chaudhuri and S. Hussain, J. Chem Sci. 2006, 118, 199.

About the author: Sahid Hussain obtained his B.S. (1999) from Science College, Jorhat; the Master (2001) from Cotton College, Gauhati University, Assam. He qualified CSIR-JRF examination and then completed his Ph.D.

(2008) degrees in Chemistry, under the supervision of Prof. M. K. Chaudhury, from the Indian Institute of Technology, Guwahati, India. Presently, he is working as a post doctoral fellow in Nanophotonics and Nanomedical Research Group, Pohang University of Science and Technology, Pohang, Republic of Korea. Effect of Solvent Media in Altering The Rates of Diel-Alder Reactions an Other C-C Bond Forming Reactions:

Dr. Diganta Sarma

Conventionally most of the organic reactions are carried out in solution phase. The solution phase, that contains pure or mixed solvents, plays a pivotal role in determining the course of reactions and the amount of product formed. There are other parameters like temperature, pressure, concentration of reactants and stability of product that are also essential in governing the course of reactions.

Scheme I However, the change of a solvent in

an organic reaction can bring about great changes in its kinetic profiles. There are several interesting properties of solvents, which may be considered significant in altering the reaction kinetics of organic reactions. The solvent media may promote the reaction rates by stabilizing the transition state. The polarity, dielectric constant, ionizing power, surface tension,



viscosity, etc. of solvents can play crucial role in directing the kinetics of organic reactions in a specific manner.

The Diels-Alder reaction is one of the

most important C-C bond forming reactions in organic chemistry to form cyclic structures. It is a class of cycloaddition reaction between a conjugated diene and an alkene, commonly termed the dienophile, to form a cyclohexene system. The remarkable importance of Diels-Alder reaction lies in the synthesis of natural products and physiologically active molecules. For a long time solvent polarity was believed to have no effect on the course of a Diels-Alder reaction due to involvement of isopolar activated complex. Berson, however, showed a clear relationship between the endo/exo product ratio and solvent polarity in the Diels-Alder reaction of cyclopentadiene and acrylates. Diels-Alder reactions in aqueous media were first carried out back in the 1930s, but no particular attention was paid to this fact until 1980, when Breslow and coworkers made the startling observation that the reaction of cyclopentadiene with butenone in water was more than 700 times faster than the same reaction in 2,2,6-trimethylpentane; whereas the reaction rate in methanol is comparable to that in a hydrocarbon solvent. Such an unusual acceleration of the Diels-Alder reaction by water was attributed to the “hydrophobic effect”, in which the hydrophobic interactions brought together the two nonpolar groups in the transition state.

Another important C-C bond

formation reaction is Michael addition. The reaction is the addition of an enolate of a ketone or aldehyde (Michael donors) to an α,β-unsaturated carbonyl compound (Michael acceptors) at the β-carbon and involves conjugate addition. The reaction donors are active methylenes such as malonates and nitroalkanes, and the acceptors are activated olefins such as α,β-unsaturated carbonyl compounds.

The conventional organic solvents

used in organic reactions are known to be environment pollutants. In view of the

environmental pollution caused by the use of these volatile organic solvents, there is a greater need to replace them by environmentally benign solvents. In this regard ionic liquids have emerged as important substitutes for several organic solvents. Many ionic liquids have been developed for specific synthetic problems. For this reason, ionic liquids have been termed “designer solvent”. Ionic liquids are considered green solvents in substituting many volatile organic solvents as they possess some special properties like: (1) They are nonvolatile, (2) They are nonflammable, (3) They have physicochemical properties that can be altered / controlled by judicious selection of the cation and/or anion and (4) Most importantly they can be recycled for a number of times without loss of activity.

Several parameters have been

discussed to explain dramatic variation in reaction rates as well as stereoselectivities in the above mentioned solvent media. The possible origin of forces includes hydrophobic packing, solvent pressure, hydrogen bonding, hydrophobic hydration, and salting-out (S-O) and salting-in (S-I) effects, etc. However, no single parameter can explain the rate profiles of all reactions studied.

The present thesis deals with

delineation and understanding of origins of possible forces responsible for rate acceleration and stereoselectivities in water, aqueous salt solutions and ionic liquids. These have been discussed in detail in seven separate chapters:

Chapter I describes a critical literature survey of the physical organic, green chemistry and asymmetric aspects of carbon-carbon bond forming reactions, in particular Diels-Alder and Michael reactions. The frontier orbital description of cycloaddition as well as mechanistic aspects of Diels-Alder reaction has been discussed. The role of secondary orbital interaction in understanding the stereochemistry of Diels-Alder reactions has been introduced. Efforts have been made to explain the special role of water highlighting the possible factors like



hydrophobic effect, hydrogen bonding, polarity, Lewis acid catalysis etc. for rate variation. Ionic liquids are emerging as potential green solvents over volatile organic solvents. Various Diels-Alder reactions carried out in ionic liquids have been emphasized. Asymmetric aspects of Diels-Alder and Michael reactions are also reported. Chapter II deals with the objectives of the investigations carried out based on the literature survey. It also describes the organization of the thesis. Chapter III is concerned with the competing role of secondary orbital interaction and hydrophobic effect in determining the stereoselectivity of Diels-Alder reactions.

In general, Diels-Alder reactions in water offer higher endo/exo ratios as compared to those in conventional organic solvents, but this is not the case for the reaction of cyclopentadiene with methyl trans crotonate (Scheme I). Secondary orbital interactions favor Diels-Alder reactions to be endo selective. But in this case hydrophobic effect of the methyl group influences the stabilization of the geometry of the transition states.

The effects of aqueous salt solutions

on the reaction of cyclopentadiene and methyl trans crotonate have been investigated. The increase in endo/exo ratios with salting-in agents like GnCl, LiClO4, urea etc and the decrease in endo/exo ratios with salting-out agents like LiCl, NaCl, NaBr, KCl, MgCl2, CaCl2 et. have been discussed in terms of hydrophobic effect.

Figure I. Ionic liquids studied

The role of cosolvents on the stereoslectivity of Diels-Alder reaction between cyclopentadiene and methyl trans crotonate has also been examined. Chapter IV discusses the Diels-Alder reactions of different dienes and dienophiles (Scheme II) in room temperature ionic liquids (Figure I).

Scheme II

The reactions have also been carried out in the presence of rare earth metal triflates to reveal increase in yields and endo/exo products. It suggests enhancement in the catalytic power of the triflates in room temperature ionic liquids. It is possible to recover and reuse the ionic liquid phase with triflates to give comparative yields and stereoselectivities even after six cycles.

.

Scheme III

+ R N O

O O

N O

O

O

R

+ N O

O

R

O

+

O

O

O

O

O

O

+

O

O

R = H, CH3, Ph

N

N

MeO

OH R

O

R

OO

N

N

HOMe

1. Hydrolysis2. Methanolysis

+ COOMeR

COOMe

R

R = H, CH3

NN(CH2)n

+ X

n=1 [EMIM]=1-ethyl-3-methylimidazolium X=BF4, PF6, Lactate,n=3 [BMIM]=1-butyl-3-methylimidazolium TFA, NTf2n=7 [OMIM]=1-octyl-3-methylimidazolium



Chapter V emphasizes the role of solvents in asymmetric Diels-Alder and Michael reactions. Methodology is based on the use of quinine as a chiral auxiliary. Quinine derived dienophiles are used to carry out asymmetric Diels-Alder reactions. After the reaction the chiral auxiliary is removed by hydrolysis (Scheme III).

Quinine derived α,β-unsaturated compounds are used to carry out asymmetric Michael reactions (Scheme IV).

Scheme IV. Chapter VI reveals the conclusions of the research work and future prospects of the studies. Chapter VII is a detailed description of the experimental procedures to carry out Diels-Alder reactions in water, salt solutions and ionic liquids. Stereochemical assignments and solubility measurements are discussed in detail. Synthesis of different ionic liquids, dienophiles and compounds for asymmetric reactions are reported. NMR spectra for product confirmation and gas chromatographs for quantitative determination of the endo/exo ratios as well as enantiomeric excess are presented.

Thus the present work focuses on the possible origin of forces responsible for the rate enhancement in Diels-Alder reactions in water, aqueous salt solutions and ionic liquids. The effect of solvents on asymmetric Diels-Alder and Michael reactions are quantified through various solvent parameters.

About the author: Diganta Sarma was born in Golaghat District, Assam. After completing his M.Sc. degree (2000) from the Department of Chemistry, Gauhati University, he went to Tezpur University to work in a MNES sponsored project. Then he moved to NEIST, Jorhat to work in the Natural Product Chemistry Division. He then joined National Chemical Laboratory, Pune to pursue his Ph.D. degree. After submitting his Ph.D. thesis in February, 2007, he immediately joined the research group of Prof. Yoshiaki Kiso, in the Department of Medicinal Chemistry, Kyoto PharmaceuticalUniversity, Kyoto, Japan. Currently, he is working on “Synthesis and structure activity relationship study of peptidomimetic coronavirus protease inhibitors.” ---------------------0----------------------

“True knowledge exists in knowing that you know nothing. And in knowing that you know nothing,

that makes you the smartest of all.”

Socrates

---------------------0----------------------

“Wise men talk because they have something to say; fools, because they have to say

something.”

Plato ---------------------0----------------------

N

N

MeO

OH CH3

O

+ ONH

O

NaH, THFON

ON

N

MeO

OH

O

1. Hydrolysis

2. Methanolysis

ON

O

O

MeO



Five Firsts in Chemistry:

American Chemical Society has compiled a Top 5 from its own publications. "Five Firsts of 2007" introduces, 1. Advances in personal security: The first molecular keypad lock appeared in January in the Journal of the American Chemical Society, promising defense and intelligence agencies a way to safeguard top-secret data using a device the size of a single molecule. Abraham Shanzer and colleagues at the Weizmann Institute of Science in Rehovot, Israel, based their molecular keypad lock on molecules that fluoresce only in response to the correct sequences of three input signals. "By harnessing the principles of molecular Boolean logic, they have designed a molecular device that mimics the operation of an electronic keypad, a common security circuit used for numerous applications in which access to an object or data is to be restricted to a limited number of persons. 2. Advances in cardiovascular disease:

The first study appeared in the Journal

of Proteome Research in July aimed at finding more effective treatments for patients for whom aspirin simply doesn't work. Blood proteins are involved in aspirin resistance, a condition that prevents thousands of patients from reaping aspirin's beneficial effects in protecting against cardiovascular disease. Antonio Lopez-Farre, Carlos Macaya, and their colleagues at the Hospital Clinico San Carlos in Madrid, used the novel technique of two-dimensional electrophoresis to study changes in different proteins present in two groups of patients (e.g: aspirin-sensitive and aspirin resistance) with coronary artery disease, the underlying cause of most heart attacks. They found increased levels of three proteins involved in the binding of vitamin D in patients with aspirin resistance. These results may aid future development of more effective therapies for aspirin-resistant patients.

3. Advances in environmental contamination:

The research appeared in the August

issue of Environmental Science & Technology. According to Neil Bruce and colleagues at the University of York, toxic TNT contamination is a major environmental problem at many World War II sites, military training areas, and explosive manufacturing sites. The researchers inserted a gene for a TNT-transforming bacterial enzyme into a tobacco plant and found that the novel bacteria could metabolize the compound into a non-toxic, non-explosive form. "This is the first report to demonstrate that transgenic plants engineered for the phytoremediation of organic pollutants can increase the functional and genetic diversity of the bacterial community in acutely polluted soil compared to wild type plants. 4. Advances in renewable energy:

This advances allowed nanotechnologists to "wire up" enzymes for producing hydrogen in fuel cells. Writing in Nano Letters, Michael Heben, Paul King, and colleagues at the National Renewable Energy Laboratory, in Golden, Colorado, have combined hydrogenases with electrically conducting carbon nanotubes to make "biohybrid" conjugate materials as components of a future hydrogen fuel cell technology. 5. Advances in genetic disease:

Scientists in California this year reported an advance toward rapid antenatal testing of Down syndrome and other chromosomal abnormalities. In an October issue of Analytical Chemistry, Stephen Quake and Christina Fan of Stanford University point out that most existing pre-natal test depend on the time-consuming method of karyotyping. The new test is based on the polymerase chain reaction (PCR) and allows DNA to be tested without the two-week cell culture step traditionally needed for karyotyping.

(Compiled by Mr. Bipul Sarma)



Introduction of Forum Members:

Miss Babita Baruwati (12th September, 1980) is originally from Jamugurihat, Sonitpur, Asom. She did her B Sc in Physics from Cotton College, Guwahati (Gauhati University) securing first class 10th position with distinction in the year 2000. She finished her M Sc Physics (High Energy, Nuclear Physics) in the year 2002 from Gauhati University securing first class 7th position. She cleared her CSIR-JRF exam in June 2002 and joined the Nanomaterials Group, Indian Institute of Chemical Technology, Hyderabad for her PhD under Dr. S. V. Manorama in March 2003. Her PhD thesis entitles “Studies on the Synthesis, Characterization, Surface Modification and Application of Nanocrystalline Nickel Ferrite”. She has published her works in eight international journals including Applied Physics Letters and Organic Letters. She has attended many national and international symposia held at several places. She will be joining Dr. R. S. Varma at National Risk Management Laboratory, Cinncinati, Ohio, USA as a postdoctoral fellow in February, 2008.

---------------------0----------------------

“Animals have these advantages over man: they never hear the clock strike, they die without

any idea of death, they have no theologians to instruct them, their last moments are not disturbed by unwelcome and unpleasant ceremonies, their funerals cost them nothing, and no one starts lawsuits over their wills.”

Voltaire

---------------------0----------------------

Mr. Bolin Chetia from Sivasagar, Assam, received Bachelor degree in Chemistry from Govt. Science College, Jorhat (Dibrugarh University) in 1999. After receiving Master degree in Chemistry (First class first position, in 2002) from Dibrugarh University, Assam (Organic Chemistry specialization), he joined as a Lecturer in the department of Chemistry, Dibrugarh University in January 2003 and serve there till April 2004. Then he moved to Regional Research Laboratory (RRL), Jorhat, as a research fellow where he worked for almost four months. He qualified CSIR-UGC JRF and GATE held in 2003. Currently he is doing his doctoral research in Indian Institute of Technology Guwahati, since December 2004. His area of research is to develop better techniques for getting nanomaterials, synthesize new hybrid materials with tunable properties and testing their catalytic, electronic properties as well as look for newer applications for chemical & biological sensors, light emitting devices, solar/photovoltaic cells (PVC) etc. During this period, he visited Kyushu Institute of Technology, Kitakyushu, Japan from 28th Aug. to 10th Sept. 2005 to deliver an invited talk entitled “Energy efficient organic-inorganic hybrid materials”.

---------------------0----------------------

I am not one who was born in the possession of

knowledge; I am one who is fond of antiquity, and earnest in seeking it there.

Confucius ---------------------0----------------------



Through The Lenses of Forum Members:

Drops of love

Twilight at Bharalu

Looking ahead

[From: Mr. Mohen Konwar and Mr. Bipul Sarma]

Free will

I am the queen

First light

Togetherness



Message:

“Helping Hands Are Better Than Praying Lips” Think and look at this…………. When you complain about your food and the food we wasted daily Hope this picture will always serve as a reminder to us that how fortunate we are and that we must never ever take things for granted.

---------------------0----------------------

Have a merry- X-mas day.

Jesus is reborn inside you like the earlier years As you asking your every prayer

Because He knows, You are the right person to be His place for reincarnation

Just you need to search out Him and give Him the place inside you Before His return for wrong reason to heaven

I know, you could handle His tenderness and delicacy Against all hardship to win peace and prosperity

Only for thousands lives Who thrives to achieve

A smile with eternal beauty Lasting ever and forever

To make this wonderful Universe always mesmerizing And marry making just like today

A very very happy merry X-mas day.

(by: Dr. Tankeswar Nath)

---------------------0----------------------



Higher Study Abroad Postdoctoral Positions:

(1) Brookhaven National Laboratory Department: Biology Location: Upton, NY, U.S.A. Start Date: 1st quater 2008 Duration: Two years

Description: This new project is under the direction of A. M. Orville, and is also associated with the PXRR group (www.px.nsls.bnl.gov) at Brookhaven National Laboratory (BNL). The PXRR group conducts research, technology development, operations, and training at six beamlines (X8, X12b, X12c, X25, X26c, X29) at the National Synchrotron Light Source (NSLS). A long-term goal for the PXRR group is to create a resource for macromolecular crystallography at NSLS-II, the new synchrotron light source that is being created at BNL during the next five to seven years. Microcrystals only a few microns along an edge are often easy to obtain; but, are typically of no use for traditional diffraction studies. In contrast, the brightness and focused beam anticipated at NSLS-II provides an ideal opportunity to use microcrystals for diffraction studies. A major barrier that remains to be overcome is how to manipulate microcrystals for structure determination. Part of the research strategy will be to use a large number of randomly oriented microcrystals, from each of which only a small fraction of the whole dataset is collected, in order to build-up the complete dataset. Full expression of these methods may approach the physical limits of crystal diffraction and will clearly help motivate the optimum performance of NSLS-II. Consequently, we will develop novel microcrystallography methods at the NSLS and look forward to utilizing the outstanding characteristics of NSLS-II facility. The position requires a Ph.D. in biochemistry, structural biology, chemistry, or physics. Experience in macromolecular crystallography and/or synchrotron x-ray sources is desired. The prospective candidate must be able to interact with a diverse group of scientists and engineers, as well as work independently. Send CV and contact information for four mentors or referees to [email protected] referring to Position No. FH4835. Other details: referring to Position No. FH4835 Please submit: CV and contact info to request 4 letters of reference Person to contact: Felicia Hartsough, FH4835 Surface mail address: Human Resources and Occupational Medicine Division, Brookhaven Nationial Lab, Upton, NY 11973 Email address: [email protected] Phone number: 631-344-2213 Fax number: 631-344-7170 Job Posted: 01/10/08 Job ID Number: 1199972727



(2) University of Dublin, Trinity College School of Pharmacy and Pharmaceutical Sciences Status: 1-2 Year Post Closing Date: Until position is filled Salary: Approximately €36,000 per annum depending on experience and

qualifications A Postdoctoral position is available in the School of Pharmacy and Pharmaceutical Sciences.The interdisciplinary project is funded by Enterprise Ireland under the Commercialization Phase; Technology Development. It involves the preclinical development of novel prodrugs capable of delivering aspirin and nitric oxide. The project is being conducted in collaboration with Prof Marek Radomski also of the School of Pharmacy. The candidate must have a PhD in Pharmaceutical or Medicinal Chemistry. He/she is expected to be highly motivated, independent and have a strong background in organic synthesis but with significant analytical experience for example in HPLC or CE. To apply, please send your CV, application letter and the name of three referees to: Dr. John F Gilmer, Pharmacy and Pharmaceutical Sciences, Trinity College Dublin, College Green, Dublin 2, Ireland , E-mail: [email protected] We welcome applications by e-mail. Please note there is no application form to be completed. (3) In Functional Organic Materials

Company/Institution: ENS Cachan Location: Cachan, France Date Posted: 7 January 2008

The Photophysics and Photochemistry of Supra- and Macromolecules laboratory (PPSM) at Ecole Normale Superieure de Cachan (ENS Cachan), located in the Paris area, is offering a one-year postdoctoral position to work on a new concept combining the photo structuration of functionalized organic or silica nanoparticles and non-destructive nonlinear read-out for 3D-optical data storage. The studies will focus on the elaboration and optical studies of novel hybrid materials in tight collaborations with physics laboratories at ENS Cachan and CEA Saclay. The PPSM lab is provided with numerous facilities for organic synthesis, material elaboration, characterizations (spin-coating, evaporation, metal sputtering, profilometer, AFM, MEB), spectroscopic equipments (steady-state UV-Vis, IR and time-resolved nano- and pico-second studies), as well as optical studies (holography, second-order NLO setups, confocal microscopes). Candidates must possess a PhD in chemistry and a solid background in organic synthesis as well as in spectroscopy or in material sciences. They must supply a covering letter describing their expertise and interest for the position, a detailed curriculum vitae and recommendation letters or list of references to the address mentioned Contract: 1-year contract with ~2200 euros gross income per month Email: [email protected] Web: http://www.ppsm.ens-cachan.fr and http://www.ida.ens-cachan.fr



(4) Harvard Medical School Department: BCMP in collaboration with Children's Hospital; Center for

Molecular and Cellular Dynamics Location: The Hub (a.k.a. Boston, USA) URL: www.employment.harvard.edu Start Date: immediately

Description: A postdoctoral position is available for a highly motivated individual to study proteins from the microRNA processing pathway. Preference will be given to candidates who have a strong background in molecular biology as well as in protein and RNA biochemistry. Experience with crystallography will be advantageous and although it is not required you must be willing to learn. Please submit application materials electronically in the pdf format. Please submit: CV, 3 references, date of availability Person to contact: Piotr Sliz, Assistant Professor of Pediatrics Surface mail address: 250 Longwood Ave, Rm SGM-130 Email address: [email protected] Phone number: 617-432-5608, ext 70 Fax number: 617-432-5600 Job Posted: 01/07/08 Job ID Number: 1199768331 (5) In Nanomagnetism

Universität Konstanz Fachbereich Physik Dr. Mathias Kläui E-mail: [email protected]

In the Department of Physics, University of Konstanz, PhD and Postdoc positions are immediately available in the field of magnetism on the nanoscale within the Junior Research Group “Nanomagnetism” funded by the European Research Council. Magnetization switching by spin-polarized current injection, rather than by using external magnetic fields has recently stirred much attention [1-3], since this novel effect has the potential for fast, reliable and simple switching, which is of great interest for applications in sensors, storage, logic [1-2] and microwave devices [3]. The underlying fundamental physical principles governing the electron-magnetization interaction are presently not well understood and in a combined experimental and theoretical study this effect will be investigated using a range of experimental techniques and numerical simulations. Low temperature magneto-transport measurements (300mK to room temperatures with fields up to 14T) will be carried out and the magnetoresistance effects will be correlated with the spin structure, which is imaged using high resolution photoemission electron microscopy, electron holography and other techniques. Using nanosecond current pulses and microwave excitations, domain walls can be displaced and the dynamics of the domain wall propagation can be measured using time-resolved magnetotransport and magnetooptical techniques. It is intended that part of the PhD/Postdoc stay can be carried out abroad at the partner institutions, such as the University of Cambridge, the École Polytechnique in Paris and others from the SpinSwitch Network (www.spinswitch.de).



Requirements: Diplom (Master or equivalent) in physics, electrical engineering, materials sciences, etc.) for a PhD position / PhD for a postdoctoral position. Knowledge in condensed matter, in particular magnetism would be advantageous. The University of Konstanz has recently been designated as one of the 9 German Elite Research Universities and the Physics department at the University of Konstanz has been consistently ranked as one of the leading departments in Germany. It is particularly strong in the area of condensed matter physics and it houses the national German Collaborative Research Centre on “Controlled Nanosystems” (SFB 767). The salary scale is TVL13 (3/4) (PhD) and TVL13 (Postdoc); in exceptional circumstances other arrangements might be possible. For enquiries and applications including a full CV contact Dr. M. Kläui (Email: [email protected],Tel.+49-7531-883786,Fax.883789

(6) Purdue University Department: Department of Biological Sciences Location: West Lafayette, Inadiana URL: www.biology.purdue.edu/people/faculty/index.php?refID=188 Start Date: ASAP

Description: A Postdoctoral position is available in the area of membrane protein structural biology at the Markey Center for Structural Biology, Department of Biological Sciences, Purdue University. We are actively pursuing structures and mechanistic studies of transporters, ion channels and receptors of biomedical importance. Preference will be given to candidates who have a strong background in X-ray crystallography and/or biophysics. Experience in protein purification and crystallization and/or membrane protein biochemistry are desirable but not necessary. The Markey Center for Structural Biology provides state of the art facilities for research and a highly interactive environment with multiple laboratories working in the area of membrane protein structural biology. Please submit via email: curriculum vita, brief summary of previous work, and the names and contact information of three references Please submit: CV, brief summary of previous work, and contact information of three references Person to contact: Dinesh Yernool Surface mail address: 915 W State St., B220, Lilly Hall, West Lafayette, IN 47907 Email address: [email protected] Phone number: 765-494-1960 Fax number: 765- 496-1189 Job Posted: 12/30/07 Job ID Number: 1199059394



Details about the Northeast India Research Forum

Date of creation of the forum: 13th November 2004 Area: Science and Technology Total number of members till date: 175 Cover page designed by: Mr. Anirban Adhikari Logo designed by: Dr. Manab Sharma Moderators: 1. Arindam Adhikari, Ph.D. Institute of Surface Chemistry, Royal Institute of Technology, Stockholm, Sweden Email: [email protected]

2. Jadab Sharma, Ph.D. Email: [email protected]

3. Utpal Borah, Ph.D. Gifu Pharmaceutical University, Japan Email: [email protected]

4. Ashim J. Thakur, Ph.D. Chemical Science Dept, Tezpur University, Tezpur, Assam Email: [email protected]

Editorial Team of NE Quest

1. Dhanapati Deka, Ph.D. Reader, School of Energy, Environment and natural reseources, Tezpur University, Assam Email: [email protected]

2. Tankeswar Nath, Ph.D. Scientist, R&D, Biotechnology, Jubilant Organosys Ltd. Gajraula, UP, India Email: [email protected]

3. Manab Sharma, Ph.D. Dept of Chemistry, Technion-Israel Institute of Technology, Israel. Email: [email protected]

4. Rashmi Rekha Devi, Ph.D Scientist, Defence Material & Stores Research & Dev. Establishment, DRDO, Kanpur. Email: [email protected]

5. Joshodeep Boruwa, Ph.D. Fachbereich Chemie, L-940 Universitat Konstanz D-78457, Konstanz, Germany Email: [email protected]

6. Pankaj Bharali, Indian Institute of Chemical Technology, Hyderabad, India. Email: [email protected]

7. Pranjal Saikia I&PC Division IICT, Hyderabad, India Email: [email protected] (Volunteer editor of this Issue )

8. Ashim Thakur, Ph.D. 9. Utpal Borah, Ph.D.

10. Arindam Adhikari, Ph.D.

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